Atomic, molecular, and optical (AMO) physics is a foundational discipline within the physical sciences. It is the study of light and matter and their interactions, and deals with electrons, atoms, molecules, and light at the quantum level. These are the fundamental building blocks of matter and their quantum-level behavior provides us fundamental understanding of the universe. At the same time, AMO is also of paramount importance for providing critical technological infrastructure for economic development, national security, and future human endeavors. These complementary features—spanning from very fundamental to very practical—provide a unique character to AMO physics, namely the rapidly evolving, strongly coupled cycles between scientific discovery and technological advances. Another powerful feature of AMO science is that it often provides the best—and sometimes, the only—viable platform to achieve certain scientific or technological goals, such as in the areas of sensing and metrology. As a consequence, the prominence of AMO physics in the scientific arena has continued to grow significantly in recent times. Atoms, molecules, and photons—all under precise control while interacting and interconnecting in the quantum regime—play decisive roles in shaping our understanding of the basic laws of nature. This control now enables researchers to manipulate quantum systems in order to tackle outstanding problems in the complexity of matter, to probe the elusive secrets of nature, and at the same time to give birth to new technologies that transform human society. In this way, AMO science offers deep and ubiquitous connections between fundamental science and applied technologies.
The historical perspective of AMO is telling. Efforts in AMO (or more traditionally, spectroscopy) led to the birth of quantum mechanics more than 100 years ago. Since that time, AMO has remained at the forefront of testing some of the most fundamental laws of nature, has stimulated the emergence of new scientific disciplines, and has provided increasingly sophisticated technical infrastructure for modern society. Today, AMO is leading the way for a renaissance of quantum physics, promising a new revolution in information processing and metrology.
A historical strength of the AMO culture is the invention, development, and construction of cutting-edge research tools, including, for example, the invention of lasers and the development of quantum information processing platforms. Another unique aspect is unusually strong close collaborations between experiment and theory. These aspects of the culture allow AMO science to open many new windows to explore deeper scientific questions, and at the same time provides a key technological underpinning for economic development. For two major U.S. National Initiatives that have emerged recently—the National Photonics Initiative and the National Quantum Initiative (NQI)—AMO science serves as the cornerstone for the foundational technologies, and the key drive to economic impact, which includes workforce training, education, industry connections, and product development.
When it comes to the ability to control physical systems—down to the level of individual quanta—AMO technology is the unchallenged leader. This ability is conducive to extracting both a rigorous understanding and the universal features from particular physical systems, and it also provides the basis for tackling increasingly more complex problems. Control, as an enabling capability, provides a natural approach for building physical understanding, and from which to design systems from the ground up. Not surprisingly, precision control also provides illuminating guidance for top-down analysis and system construction. The now pervasive control of simple quantum systems starts from single photons and single atoms and molecules. Building from there, this control has provided a rich arena for AMO scientists to tackle both systems that are more complex and more strongly interacting. This capability has, for example, been crucial to the development of the basic infrastructure for the emergence of quantum information science (QIS). Control allows bridging the gap from few- to many-body physics, and understanding and manipulating quantum coherence, complexity, and dynamics. Together these features position AMO to drive the next revolution in measurement that could provide answers to some of the most fundamental questions concerning physics, and could offer new opportunities to explore grand challenges in both science and technology.
As previously suggested, AMO is strongly positioned among all disciplines of the physical sciences in that it plays a central role in connecting intellectual
frontiers and technological foundations. It does so not just within AMO physics, but broadly. It does this for astrophysics; condensed-matter, plasma, high-energy, particle, and nuclear physics; gravitation and cosmology; chemistry; biology; and health. It is a key driver behind the quantum information revolution. Numerous AMO researchers have garnered international recognition for their accomplishments, the annual Nobel Prize being perhaps the most universally revered. Since 2004, the time of publication of the previous decadal study, 20 scientists have been awarded Nobel Prizes in Physics for research that related to AMO science. These include Ashkin for optical tweezers and applications to biological systems (2018); Mourou and Strickland for generation of high-intensity, ultrashort optical pulses (2018); Weiss, Thorne, and Barish for the observation of gravitational waves (2017); Akasaki, Amano, and Nakamura for the invention of blue light emitting diodes, which has enabled bright and energy-saving white light sources (2014); Haroche and Wineland for methods that enable measuring and manipulation of single quantum systems (2012); Kao for transmission of light in fibers for telecommunications (2009); Boyle and Smith for the invention of an imaging semiconductor circuit—the charge-coupled device sensor (2009); Glauber for the quantum theory of optical coherence (2005); and Hall and Hänsch for precision spectroscopy and optical frequency combs (2005). The reach of AMO science is felt beyond physics, and indeed the 2014 Nobel Prize in Chemistry was awarded to Betzig, Hell, and Moerner for the development of super-resolved fluorescence microscopy.
In addition to the Nobel Prize, the Kavli Prize, the Breakthrough Prize, and the Wolf Prize are symbols of recognition of scientific eminence. Here too, AMO science has fared very well, with nearly a dozen prize recipients recognized for AMO-related science in the past decade.
Perhaps the biggest international recognition for AMO research is the widespread support for AMO among all leading industrialized countries, including rising national funding and improved educational efforts. The purpose of this report is to reflect on these successes, and to identify the most pressing current challenges as well as the most promising future opportunities in AMO science.
In this spirit, the committee structures this decadal report to highlight the scientific achievements from the past decade, and to identify the great opportunities that lie ahead in the field of AMO sciences. These include scientific discoveries within AMO and a wide range of applications that will be based on them. The committee outlines six major scientific themes that form the core of AMO science, presented in the following six chapters: “Tools Made of Light,” “Emerging Phenomena from Few- to Many-Body Systems,” “Foundations of Quantum Information Science and Technology,” “Harnessing Quantum Dynamics in the Time and Frequency Domains,” “Precision Frontier and Fundamental Nature of the Universe,” and “Broader Impact of AMO Science.”
These six closely connected grand challenge themes represent numerous recent scientific accomplishments and key scientific opportunities. Each theme discussion contains three components—fundamental science, technological development and tools, and broad impact. A tool developed under one theme may enable the exploration of science in another, which in turn may open powerful applications in a third theme. As a result, there is strong overlap across chapters in terms of both science and technological tools. This theme-oriented structure for this report differs from a more traditional categorization of individual areas of the AMO field, such as ultracold, ultrafast, or ultraprecision physics. Instead, the committee integrates these traditionally identified areas, which then permeate the entire report through the multiple scientific themes. For example, a reader who is an expert in the control of light will find relevant discussions of his or her work in chapters where it is the main subject of research, and also in chapters where it provides essentials tools for quantum state control and precision measurement, and yet in other chapters where new physical systems provide novel opportunities with their light sources. The discussion on ultracold matter centers on emerging phenomena in many-body systems, and provides an intimate connection to QIS. Below, the committee briefly outlines each of the six scientific themes that are presented in this report. Interconnected together, the goal is for these six themes to form a coherent overview of AMO science, and for the reader to appreciate the universal connections between scientific vision and technology development within AMO.
The invention of new light sources has always been a path toward obtaining deeper understanding of the physical world, from seeking its finer structure to following more rapidly changing behaviors. Further, the development of light sources is, in itself, a scientific venture that requires utmost control of atoms and molecules, accelerated electrons, collective states of atoms, and solid-state environments. The field of AMO seeks to create and harness a variety of new light sources that advance multiple metrics for the control of electromagnetic radiation: ultrashort light pulses from the extreme ultraviolet (XUV) to the X-ray domain, extreme high-intensity laser fields, highly nonclassical light, and extremely coherent light, as examples. These light sources, each specifically tailored for corresponding scientific explorations, allow researchers to advance the frontiers of spectroscopy, to establish new networks including quantum communications and computing, and to explore phenomena that occur under the extreme conditions of ultrahigh fields or at ultrashort time scales. At the same time, the integration of light and matter, in the form of novel nanophotonic structures or large-scale interferometers as just two examples, provides the next technological frontiers for manufacturing mass-scaled and transportable devices.
By precisely probing the microscopic underpinnings of emergent phenomena in quantum matter, interacting, many-body quantum systems can be studied and understood. In this process, new insights are gained into the emergence of universal rules that govern complex materials and inspire novel quantum measurement approaches for exploring unknown corners of our physical world. On the one hand, an interacting many-body quantum system presents fundamental challenges to the understanding of its properties. On the other hand, once understood and controlled, such a system turns into a tool for fundamental gains in measurement and information processing, at the same time expanding the range of science and creating new technology.
To provide the enabling technical capabilities and key insights to the emergence of complexity, researchers need to build quantum matter from well-controlled quantum particles and excitations, from constituents ranging from photons, atoms, molecules, and nano-quantum components. A common theme is the ability to gather many constituents while still accessing measurement at the single-particle level. Second, we need to understand and manipulate interactions between individual quantum particles, through the use of key ingredients such as time-dependent drives, engineered reservoirs, controlled geometry and topology, disorder and frustration, and quantum entanglement. The realization of new forms of quantum matter advances our understanding of complex quantum behavior and provides guiding principles for discovery of advanced materials and novel technologies. Furthermore, precisely controlled quantum systems that are necessary for this line of research provide natural platforms for quantum information processing, a subject for the following chapter discussion.
The production, transmission, and use of quantum bits (qubits) offer tremendous promise for computation, simulation, communication, sensing, and network performance beyond current technological limits. Very likely, quantum information processing (QIP) will rely on multiple platforms, each with different strengths and shortcomings, for storing, manipulating, and transporting quantum information. Great opportunities and challenges exist in parallel. On the one hand, open questions related to the fundamentals of QIS still need to be explored and addressed; on the other hand, a range of novel QIP tools and techniques based on precisely controllable and measurable quantum systems need to be developed now to foster the growth of quantum technology.
AMO systems, including ultracold neutral atoms and molecules, trapped ions, and quantum states of light, have been essential for the development of all areas of quantum information science and technology (QIST). Optical lattices or tweezers filled to unity with ultracold atoms, and soon also molecules, constitute large arrays of perfectly identical qubits, in which quantum information can be stored in hyperfine or other internal states with essentially unlimited energy relaxation times, each of which can be addressed and measured with optical microscopy. Tightly focused optical traps provide a new and rapid means to assemble such quantum-bit arrays. Linear chains of identical trapped ions were among the first systems with which to realize digital quantum computing, and feature very high controllability and gate fidelity. Quantum optical systems provide resources for the transmission of quantum information and for quantum-secure communication. Neutral atom and trapped ion platforms allow for large-scale quantum simulation, with particular application to studying quantum effects in materials, and giving unprecedented experimental access to the non-equilibrium dynamics of quantum systems. The high level of control over quantum coherent states in AMO systems finds immediate application in sensing and precision measurement. It is through such applications that the present-day, less than 100 percent fidelity, and intermediate-scale quantum technologies may have their greatest impact, both in fundamental science and in a wide range of technologies.
AMO science will continue to play a leading role in this exciting research direction. To broadly advance the goals of QIP, a number of important technological developments must take place simultaneously. Although “technological” in thrust, all still require significant scientific development as well. These scientific explorations and technological developments will prepare the scientific community to further our understandings of foundational quantum physics and build an advanced QIS infrastructure consisting of the following:
- Communication, to guarantee secure data transmission and long-term security for information using entanglement-based, resilient, distributed quantum networks;
- Computation, to solve problems beyond the reach of current or conceivable classical processors by using programmable, high-fidelity quantum machines;
- Simulation, to understand and solve important problems—for example, chemical processes, new materials, as well as fundamental physical theories, by mapping them onto controlled quantum systems in an analog or digital way;
- Sensing and metrology, to achieve unprecedented sensitivity, accuracy, and resolution in measurement and diagnostics by coherently manipulating quantum objects.
A key scientific goal is to observe the dynamics and transformations of different forms of quantum matter on their natural time scales, spanning more than 10 orders of magnitude. These out-of-equilibrium dynamics often involve or create strong correlations and entanglement, and can be exceedingly difficult to observe and understand, owing to the daunting need to develop new investigative tools in both experiment and theory. This represents a grand challenge for both scientific and technological applications.
At the ultrafast time scale, molecular movies that can resolve chemical and biological transformations from the fastest electron dynamics through the relatively slower structural changes and chemical transformations offer the promise of gaining fundamental insights as well as developing biochemical applications. Furthermore, the control of coherent, subfemtosecond electron dynamics in molecules and solids can reveal and change important material characteristics, and at the same time have implications for information processing technology. The exploration of these dynamics is enabled by frontier light sources that yield femtosecond and subfemtosecond pulses spanning the infrared to the hard X-ray spectral range. With full control of the light field’s amplitude, phase, and temporal structure, high-energy light sources provide an ideal tool for many powerful applications, including capturing the fastest electron dynamics in matter and helping reveal how electron scattering and screening occur on subfemtosecond time scales.
Transformational dynamics can occur at very different time scales, even though they could be governed by the same underlying physics, from the ultraslow (like the cold atoms discussed in Chapter 3) to the ultrafast (Chapter 5), and its probing via time-resolved spectroscopy thus provides a point of connection between different themes in this report. For example, the combination of molecular quantum-state control (Chapter 3) and frequency comb spectroscopy (Chapters 2 and 5), with its simultaneous high resolution in both time and frequency, permit direct and real-time detection of chemical species that provide an invaluable link to the fundamental understanding of reaction kinetics.
AMO-based measurement science has advanced our fundamental understanding of the physical world, but, perhaps surprisingly, the deepest secrets of our universe are still waiting to be discovered. A major scientific theme within AMO is the ability to engineer new quantum systems to provide the next generation of measurement techniques to search for new physics. Additionally, foundations of
quantum mechanics can be explored in simple AMO-based table-top experiments and basic models. By taking advantage of AMO techniques and fundamental understandings gained from quantum-controlled states and correlations, we turn them into quantum resources for advancing measurement sciences broadly. New table-top AMO experiments will be devised, and existing ones advanced to the next performance frontiers. These advances will probe fundamental science that complements existing approaches in high-energy, particle, and astrophysics.
The scale and discovery potential of the AMO effort to search for new physics have increased dramatically over the past decade. AMO fundamental physics now encompass a wide array of diverse experiments, including searches for permanent electric dipole moments, tests of the fundamental symmetries such as charge, parity, and time (CPT) and Lorentz symmetry; searches for variations of fundamental constants; studies of parity violation; tests of quantum electrodynamics; tests of general relativity and the equivalence principle; searches for dark matter, dark energy, and extra forces; and tests of the spin-statistics theorem. This progress is expected to accelerate in the coming decade, armed with development of new technologies, advances in AMO theory, and plentiful ideas for new searches.
AMO science also plays an important role in astrophysical probes of the universe, such as the recent discoveries of gravitational wave sources with the precision interferometers of the Laser Interferometer Gravitational-Wave Observatory (LIGO) and Virgo. With important discovery potential for the detection of new forces and in establishing new observatories for the universe based on AMO technologies, it is time for the scientific community to consider more seriously the potential of AMO in space. Access to space and microgravity is a unique tool for AMO science that enables both higher precision measurements and the possibility to carry out experiments that are impossible on Earth. The United States played an early leadership role for experiments in space with the 1992 Lambda Point Experiment that used superfluid helium onboard STS-52 to probe the renormalization group theory of phase transitions. Recently the National Aeronautics and Space Administration (NASA) has invested a large effort in establishing a Cold Atom Laboratory on board the International Space Station. Other nations have now caught up to the United States in this arena and have exceeded our capabilities in some regards. Conducting AMO research in space should also lead to key technological advances such as placing quantum sensors in orbit for navigation and establishing a quantum communication network.
AMO has played and will continue to play a central role in providing inspirational scientific insights and enabling capabilities for other areas of scientific and technological development. These areas range from fundamental physics to other
subdisciplines within physics, as well as to chemistry, biology, and material science, to advanced manufacturing and engineering, and to workforce training and industrial partnership. The connections between AMO and other fields foster forward-looking and synergistic research directions. While sometimes it is useful to distinguish projects that are within the AMO field’s central scope from those that are not, such boundaries must be permeable, to enhance the bidirectional flow of ideas, to enable AMO to evolve in response to new developments in other areas of science, and to maximize our field’s potential broader impact. As examples, AMO science has both known and unexplored applications to biological systems, to astrophysics, to plasma, nuclear, and high-energy physics, and to quantum and classical information technologies. These connections must be nurtured while not losing focus on the core missions of AMO science.
Another critically important “broader impact” concerns connections to industry, and education of the next generation of a workforce capable of advancing our increasingly technological modern society. AMO has traditionally worked hand in hand with industry to improve the performance of components used in advanced experiments while also providing innovative commercial opportunities. Manufacturers of lasers, optics, and photodetectors have contributed to the advanced AMO experimental platforms with unprecedented precision and control. These systems have in turn stimulated the development of practical sensors, industry standards, and metrological instrumentations.
Chapters 2 through 7 highlight the amazing achievements of AMO science over the past decade, and identify opportunities for scientific discoveries and new technological development in the coming decade. In doing so, the committee provides a summary review of the field of AMO science as a whole, and uses case studies in selected, nonprioritized sub-disciplines in AMO science to describe the impact that AMO science has on other scientific fields. The structure of the report is designed to help readers to readily identify scientific grand challenges, with science goals, tool development, and impact all interleaved throughout the chapters. This allows identification of opportunities and challenges associated with pursuing research in specific fields as well as in interdisciplinary areas. Additionally, these summaries provide a guideline to identify the impacts of AMO science, now and in the near future, on emerging technologies and in meeting national needs.
Following these brief summaries of the six technical chapters, the committee next turns to discuss one of the main goals of this report, which is to provide insights for scientists and federal agencies alike in exploring opportunities to advance both established and emerging areas of AMO, through funding, education, and
industrial partnerships, and so on. Of course, the foremost observation is that past achievements lay the foundation for new discoveries.
AMO science does not, however, get done in isolation from the economic and societal structures in which the community operates. Chapter 8 examines the state of the field of AMO science in relation to these structures, and addresses issues of funding, workforce development, and demographic challenges. We also draw attention to the growing concerns about increasingly restrictive U.S. immigration policies and the threat to healthy international collaboration. These issues are, of course, not independent of each other, and the committee tries to make connections when possible. Through the data the committee have collected and analyzed, and by sharpening our findings and recommendations, the committee sought to address the following components of the statement of task below, and in more detail in Chapter 8:
- Evaluate recent trends in investments in AMO research in the United States relative to similar research that is taking place internationally, and provide recommendations for either securing leadership in the United States for certain subfields of AMO science, where appropriate, or for enhancing collaboration and coordination of such research support, where appropriate;
- Identify future workforce, societal, and educational needs for AMO science;
- Make recommendations on how the U.S. research enterprise might realize the full potential of AMO science.
Continued advances in the grand challenges identified in this report, and in the broader frontier of AMO science generally, will rely on a number of key factors.
The first key issue is the education of the next generation of AMO scientists. We must strive to stimulate and nurture students’ interest in AMO from early stages of their studies. For talented young researchers, we should provide ample opportunities to foster their emergence as the next AMO leaders. Considering the shifting societal demographics, another important question to address is how to further diversify the future AMO workforce to include the largest possible talent pool. To facilitate the development of practical applications and technology transfer, effective workforce training and industry partnership must be considered and implemented.
In order to ensure that opportunities in AMO sciences are accessible to and benefit from a diverse set of practitioners, the committee strove to examine the
level of participation of women and underrepresented minorities. The committee has thus collected available data from the professional societies and from the federal funding agencies that fund or support AMO research. It was not possible to get accurate data in some cases. The lack of data on demographic trends in AMO funding and education—whether the data were not collected or were not made available for this study—was a significant impediment in addressing certain elements of the Statement of Task. Whenever available, these data have been used to infer education, professional development, and funding opportunities for women and underrepresented minorities.
Other important issues pertaining to the entire AMO field include examining the balance of support for theory and experiment. A tremendously successful ingredient in AMO has been the strong collaboration between experiment and theory. It is already part of the AMO culture that some scientists who are expert experimentalists are also excellent theorists, and theorists actively participate in experimental designs and data analysis. If the expertise and excellence in each area, and the collaboration between them, can be further strengthened, then AMO will be well poised for the challenges of the coming decade.
Another critical balance that needs careful consideration is between tabletop and large-scale experiments. Nimble, small-scale experiments are the historical trademark for AMO. However, AMO did give rise to some large-scale science historically. Today we are facing unprecedented opportunities to take on some of the biggest questions in science, based on AMO approaches. Some of these require larger-scale collaborations rather than the typical table-top experiments, such as searches for new physics beyond the standard model or gravitational wave detection. The committee believes that these new opportunities should be encouraged and supported, as they have the potential to lead to groundbreaking discoveries at an accelerated pace. As pointed out in Chapter 6, the connection between AMO science and space environments should also be established with renewed enthusiasm and strong support, as there are tremendous opportunities here.
The rapid progress in AMO science is the direct result of strong investments made by the federal government’s research and development agencies in the work of AMO researchers. To gauge the impact of federal funding on AMO research, and to find ways to further enhance its effectiveness, the committee also sought answers to questions on funding trends and distributions. These are presented in detail in Chapter 8. However, the committee notes here that data are collected in different ways at different agencies, and even the definition of AMO is not the same throughout. As a result, the committee was somewhat limited in the scope of the conclusions it has been able to draw.
AMO science has been pursued in academia, national laboratories, and industry, and it has been greatly enhanced by collaborations between these different
research venues. The committee also found it important to explore and understand interagency activities and partnerships to strengthen such collaborations, especially in areas where grand challenge problems are to be tackled. For example, the National Science Foundation (NSF), National Institute of Standards and Technology (NIST), and Department of Energy (DOE) are discussing how to work together on quantum information–related initiatives, where it will be important to combine resources and strengths to advance a few key breakthroughs in quantum technology. International connections and collaborations have historically played a pivotal role in accelerating the development and achievements of science and technology in AMO, and in fulfilling shared educational goals. This should be strongly encouraged to continue. Obtaining more than anecdotal data to understand existing interconnections between agencies, with industry, and internationally proved to be especially difficult, so the committee had to draw primarily on our collective experience rather than hard data.
The timing of this AMO decadal survey overlaps well with the increasing effort on QIST as outlined in the recent National Research Council report on the NQI. An entire chapter (Chapter 4) is devoted to addressing this important topic, and the committee emphasizes that AMO continues to play a pivotal role for QIST. Not only does AMO help tackle some of the most fundamental questions related to quantum state engineering, entanglement generation and measurement, and controlled scaling of the number of qubits, but AMO also provides key enabling technologies and some of the most promising platforms that are critical for QIS. In light of the strong national interest in QIST, as seen by the strong support for the NQI, it is clear that AMO will continue to receive a broad base of support for both basic science and emerging technologies, and will play a vital role in creating new opportunities, making foundational discoveries, and providing key enabling technologies for the progress of QIST.
The committee offers the following findings and recommendations on the AMO scientific front and on government support for AMO. The committee supports each recommendation with a set of findings that the committee has made during the course of this study. These recommendations can be taken to strengthen our responses to specific grand challenges and to broadly advance the entire scientific frontier of AMO.
Finding: The historical strength of AMO has been in its core curiosity-driven AMO research programs, which have been the driving force behind many new scientific discoveries and innovative technologies, including the recent emergence of quantum technology.
Key Recommendation: It is vital that the U.S. government see curiosity-driven atomic, molecular, and optical science as a critical investment in our economic and national security interests and vigorously continue that investment to enable exploration of a diverse set of scientific ideas and approaches.
Finding: The development of QIST is progressing rapidly, and, while the time is ripe to invest in quantum technology based on specific existing platforms, there is also a large and growing number of possible new systems and platforms one can exploit for construction of quantum machines.
Finding: The development of quantum technology is still at a very early stage, and the state of the art is evolving very rapidly. It is too soon to develop governmental standards; however, for the health of the field, the committee finds it is urgent for the research community to develop platform-independent metrics to measure quantum advantage and to characterize the true scientific impact of quantum advantage.
Key Recommendation: Basic research in science, engineering, and applications underlying both existing and emerging new platforms needs to be broadly supported, including research on techniques for cross-verification of quantum machines across different platforms for various applications. Specifically, the committee recommends that the National Science Foundation, Department of Energy, National Institute of Standards and Technology, and Department of Defense should provide coordinated support for scientific development, engineering, and early applications of AMO-based quantum information systems.
Finding: Creative science carried out by single principal investigator (PI) groups is the heart of AMO science. The field does best building on these individual investigators, but it is entering a new phase where collaborations with flexible-size teams would enable exciting new discoveries.
Finding: The development of quantum technology is bringing new opportunities in sensing and precision measurement. However, nurturing these opportunities that impact other areas of science requires long-term investments that cross traditional disciplinary boundaries.
Finding: In particular, rapid advances in the precision and capabilities of AMO technologies have dramatically increased the potential of AMO-based techniques to discover new physics beyond the Standard Model. The present
lack of a federal funding program dedicated specifically to supporting such research at the intersection of high-energy physics and AMO is a limiting factor in fully utilizing the plethora of opportunities for new discoveries.
Key Recommendation: The Department of Energy’s High-Energy Physics, Nuclear Physics, and Basic Energy Sciences programs should fund research on quantum sensing and pursue beyond-the-Standard-Model fundamental physics questions through AMO-based projects.
Finding: AMO tools, techniques, and data enable the observation and in-depth understanding of a variety of astrophysical phenomena.
Finding: State-of-the-art astrophysical observations have identified the need for further development in theoretical and experimental AMO physics, which can help provide in-depth understanding of the cosmos. Addressing these opportunities would require strong interagency coordination that supports AMO and astrophysics.
Finding: The time is ripe for recently developed AMO tools and technologies to be deployed in space missions.
Key Recommendation: The National Aeronautics and Space Administration, in coordination with other federal agencies, should increase investments in theory and experiment for both space- and laboratory-based fundamental atomic, molecular, and optical science that are needed to address key questions in astronomy, astrophysics, and cosmology.
Finding: AMO tools in attosecond and X-ray science are being used to explore a broad range of interdisciplinary topics having implications in chemistry, materials science, and technology. The U.S. position in terms of investment and commercialization in this area has weakened compared to Europe and Asia.
Finding: The 2018 National Academies of Sciences, Engineering, and Medicine report Opportunities in Intense Ultrafast Lasers: Reaching for the Brightest Light recommended that DOE lead the development of a comprehensive interagency strategy for high-intensity lasers that includes the development and operation of both large-scale national laboratory projects and mid-scale university-hosted projects.
Key Recommendation: U.S. federal agencies should invest in a broad range of science that takes advantage of ultrafast X-ray light source facilities, while
maintaining a strong single principal investigator funding model. This includes the establishment of open user facilities in mid-scale university-hosted settings.
Finding: Experimental AMO science has become very expensive, and making the down payment to start up a new experimental program has become a deterrent for young AMO scientists being appointed as faculty in academia.
Finding: Strong theory-experimental collaboration has been important for maintaining the health of AMO science. However, the number of faculty positions in AMO theory has been limited.
Finding: There are existing successful portable funding models in the United States and Europe, such as National Institutes of Health (NIH)-K99, and European Research Council grants, that could be used as models to assist faculty appointment and early career development. However, an aspect of the NIH-K99 that would not be appropriate for the U.S. academic physical science community is the level of research effort requirement that makes it incompatible with standard teaching expectations.
Finding: Departmental boundaries create barriers for young AMO-trained post-docs to move into related disciplines and departments, such as QIS, computer science, and electrical and mechanical engineering, where their AMO training could play key roles in advancing those fields.
Key Recommendation: AMO funding agencies should develop portable fellowship grant models that support the transition of AMO science theorists and experimentalists into faculty positions.
Finding: AMO science, like other physics disciplines, continues to have difficulty in attracting women and underrepresented minorities at all levels.
Finding: It is clear that education and workforce development in AMO is not keeping up with the demographic shifts in the nation, and that this is a lost opportunity.
Key Recommendation: The entire AMO science enterprise should find ways to tap into the growing national talent pool of women and underrepresented minorities. The committee therefore endorses the relevant recommendations in the National Academies of Sciences, Engineering, and Medicine
report Graduate STEM Education for the 21st Century and Expanding Underrepresented Minority Participation, for example.
Finding: Quantum technology cuts across scientific fields and technologies beyond AMO, and so encounters barriers with traditional funding mechanisms.
Finding: Recent Quantum Leap Initiatives at NSF are based on a stewardship model that starts to break the traditional discipline barriers.
Finding: Traditional AMO training focuses on physics; however, the development of quantum technology requires reaching across both academic disciplines and industry to leverage the impact of AMO.
Finding: AMO technologies are not being transferred into other fields for use as rapidly as AMO science itself develops. It is increasingly important to let other fields become aware of AMO. The breakneck pace of AMO leads the committee to believe that other communities would benefit from knowing more about AMO.
Key Recommendation: The National Science Foundation, Department of Energy, National Institute of Standards and Technology, and Department of Defense should increase opportunities for translating atomic, molecular, and optical science advances to other fields by fostering collaboration with scientists and engineers from other disciplines through, for example, support of workshops and similar mechanisms for cross-disciplinary interactions.
Key Recommendation: To maximize the effectiveness of federal investment, academia should enable and encourage cross-disciplinary hiring of theorists and experimentalists at the rapidly growing interface between AMO science fields and computer science, mathematics, chemistry, biology, engineering, as well as hiring into industry.
Finding: The health of AMO science relies heavily on strong international collaborations. However, there exist a number of technical and regulatory impediments, including major differences in effort certification, intellectual property ownership policies and conflict-of-interest rules, as well as unfunded external audit requirements and unreasonable currency exchange requirements, all of which make it difficult for U.S. universities to accept and administer grants from, for example, the European Union. While the committee recognizes the significance of potential national security issues, there is great national ben-
efit in having intellectual leaders visiting the United States. This benefit is at risk due to continuing significant issues affecting access to national research facilities and excessive visa delays for international students, collaborators, and speakers at conferences.
Finding: Mechanisms for co-funding research that is carried out with international collaboration fuels collective progress in AMO science.
Key Recommendation: The committee recognizes the real security concerns in open, international collaboration. However, because open collaborations have been so vital for the health of atomic, molecular, and optical physics, the Office of Science and Technology Policy and federal funding agencies should work collaboratively with the Department of State and an academic consortium such as the Council on Governmental Relations to remove impediments to international cooperation. There is a critical need for
- Blanket agreements for funding agencies in different countries to accept each other’s grant administration regulations;
- Standardized mechanisms for joint funding of cooperative projects; and
- Mechanisms to remove excessive visa application delays for international students, collaborators, and speakers at U.S. conferences and workshops.
Finding: The past decade has seen revolutionary advancements in ultrafast light source development spanning the XUV and X-ray spectral regime. The ability to control and manipulate these tools made of light is enabling new applications that extend beyond AMO physics. New platforms are emerging in QIS, remote sensing, and clocking ultrafast electron dynamics in all phases of matter. Thus, the frontiers lie at the interdisciplinary intersection of physics, engineering, chemistry, materials science, and biology.
Finding: Advances in ultrafast X-ray science has become increasingly demanding of resources that are beyond the ability of single PI funding models. X-ray free-electron lasers are large-scale facilities that need the management infrastructure of a National Laboratory. However, table-top systems, such as attosecond- and petawatt-class lasers, have evolved to the level of a mid-scale facility requiring operational management and safety infrastructure. The
United States has lagged behind the rest of the world in capitalizing on the opportunities enabled by these mid-scale facilities, training of a workforce at the cutting edge of technology, and the economic benefits of industrial growth.
Key Recommendation: U.S. federal agencies should invest in a broad range of science that takes advantage of ultrafast X-ray light source facilities, while maintaining a strong single principal investigator funding model. This includes the establishment of user facilities in mid-scale university-hosted settings.
Finding: Despite the enormous advances of integrated linear and nonlinear photonics based on silicon, there is a need for ultra-low-loss platforms where light can be generated with ultrahigh efficiency, switched and detected, especially for quantum-related applications. Such a platform would probably be formed via the integration of multiple materials on silicon.
Finding: Systems exhibiting strong photon-photon interactions are currently being explored, to enable unique applications such as quantum-by-quantum control of light fields, single-photon switches and transistors, all-optical deterministic quantum logic, the realization of quantum networks for long-distance quantum communication, and the exploration of novel strongly correlated states of light and matter.
Finding: As nanofabrication technologies and the availability of high optical quality, low thermal dissipation materials improve, design and control of the mechanical oscillators will get more sophisticated. The lower thermal noise of future oscillators will allow quantum fluctuations to fully dominate the motion of the mechanical oscillators, perhaps even at room temperature, creating a versatile quantum resource for a variety of applications.
Key Recommendation: The federal government should provide funding opportunities for both basic and applied research that enables the development of industrial platforms, such as foundry offerings, and interdisciplinary academic laboratories to support the integration of photonics and engineered quantum matter.
Finding: Few-body physics continues to be of continuing interest to identify and test the scope of quantum universality, for its intrinsic intellectual interest, its connections with many-body physics, and to strengthen the controllability
of both few-body and many-body quantum systems. Developing theoretical tools able to quantitatively predict the behavior and interactions of increasingly complex atoms and molecules is crucial for further developments in these areas.
Finding: Due to recent theoretical and experimental breakthroughs, ultracold molecules now constitute a very promising research platform able to tackle diverse many-body phenomena and explorations of fundamental reactive processes, with certain molecules yielding viable targets for precision measurement science.
Finding: Trapped ion systems, neutral atoms, systems with long-range interactions (such as those based on molecules and Rydberg atoms) and ion-neutral hybrid systems are leading candidates for quantum information processing and simulation, and for studying chemical dynamical processes.
Recommendation: The AMO science community should aggressively pursue, and federal agencies should support, the development of enhanced control of cold atoms and molecules, which is the foundational work for future advances in quantum information processing, precision measurement, and many-body physics.
Finding: Quantum gases of atoms and molecules enable controlled exploration of equilibrium and non-equilibrium many-body physics and the generation and manipulation of entangled states applicable to quantum information processing and quantum metrology, and further developing our understanding of deep questions such as the nature of thermalization, many-body localization, and stable quantum matter away from equilibrium.
Recommendation: Federal funding agencies should initiate new programs to support interdisciplinary research on both highly correlated equilibrium phases and non-equilibrium many-body systems and novel applications.
Finding: AMO-based quantum simulators have the ability in the short term to demonstrate genuine quantum advantage over classical computational devices, without requiring the mastery of complex quantum gates required for a universal digital quantum computer. These systems can provide unique insights into complex models from condensed-matter and high-energy physics, and lead to development and testing of useful quantum algorithms.
Recommendation: Federal funding agencies should initiate new programs involving development, engineering, and deploying the most advanced
programmable quantum simulator platforms, and make these systems accessible to the broader community of scientists and engineers.
Finding: There are many possible systems and platforms for construction of quantum machines. The technology development is still at a very early stage and the state of the art is evolving very rapidly.
Finding: The federal government has decided to pursue a “science first” policy for QIS.
Recommendation: In support of the National Quantum Initiative, federal funding agencies should broadly support the basic research underlying quantum information science.
Recommendation: Academia and industry should work together to enable, support, and integrate cutting-edge basic research, complemented by focused engineering efforts for the most advanced quantum information science platforms.
Recommendation: The Department of Energy and other federal agencies should encourage medium-scale collaborations in quantum information science among academia, national laboratories, and industry.
Finding: The Department of Defense has a long history of supporting AMO research as part of its mission. This has been richly rewarded by numerous developments including the laser, GPS, optics, and a multitude of sensors. More recently, NIST and NSF have joined with DoD, leading to the emergence and nurturing of all aspects of QIS. Most recently, DOE is expected to play a major role in NQI.
Recommendation: (a) The Department of Defense (DoD) should continue both this foundational support for novel developments and the exploitation of the resulting technologies. (b) U.S. funding agencies participating in the National Quantum Initiative (NQI) should collaborate with each other and with DoD to build on the long history in quantum information science when developing their plans under NQI. (c) Department of Energy and its laboratories should develop strong collaborations with leading academic institutions and other U.S. funding agencies to realize the full potential of QIS.
Finding: This is a unique time in ultrafast science due to the ubiquity and controllability of ultrafast light sources spanning the terahertz through the hard X-ray regime. The development and application of these sources have driven much of the progress described in this chapter.
Finding: Control of ultrafast electron dynamics in molecular and condensed-phase systems has significant potential for impact well beyond AMO science, including at the technological and industrial levels. Likewise, continued development of molecular movies will drive advances at the fundamental level, and promises societal benefits through improved understanding of photo-driven biological processes.
Finding: Continued progress on these challenges will require the combined expertise of multiple PIs and mid-scale infrastructure, either because they involve advanced facilities with many different elements, or because they are inherently multidisciplinary in nature, covering AMO, condensed-matter physics, chemistry, laser technology, and large-scale computation. Funding mechanisms similar to the Physics Frontiers Centers or Multidisciplinary University Research Initiatives, in which multiple PIs from experiment and theory work toward a common goal, are crucial.
Key Recommendation: U.S. federal agencies should invest in a broad range of science that takes advantage of ultrafast X-ray light source facilities, while maintaining a strong single principal investigator funding model. This includes the establishment of open user facilities in mid-scale university-hosted settings.
Finding: There has been widespread use of data typically gathered in collision physics and spectroscopy, which are needed for applications and analysis in astrophysics, plasma physics, and nuclear medicine among others, as well as a decline in university-supported collision physics and spectroscopy groups.
Recommendation: National laboratories and NASA should secure the continuation of collision physics and spectroscopy expertise in their research portfolios.
Finding: Rapid advances in the precision and capabilities of AMO technologies have dramatically increased the potential of AMO-based techniques to discover
new physics beyond the Standard Model. The present lack of a federal funding program dedicated specifically to supporting such research at the intersection of high-energy physics and AMO is a limiting factor in fully utilizing the plethora of opportunities for new discoveries.
Finding: Supporting and promoting much stronger joint efforts between AMO physics, particle physics, gravitational physics, astrophysics, and cosmology is necessary to promote creative ideas and new opportunities for grand challenge discoveries with AMO-based science.
Finding: The United States is falling behind in deploying a diverse set of AMO precision measurement platforms and integrating tools into dedicated devices to maximize discovery potential.
Finding: International collaborations are needed for full realization of AMO-based science discovery potential.
Key Recommendation: The Department of Energy’s High-Energy Physics, Nuclear Physics, and Basic Energy Sciences programs should fund research on quantum sensing and pursue beyond-the-Standard-Model fundamental physics questions through AMO science-based projects.
Recommendation: Federal funding agencies should modify funding structures to allow for theoretical and experimental collaborations aimed at AMO science-based searches for new physics and development of diverse set of AMO precision measurement platforms including larger (more than five principal investigators) and long-term (10-year) projects.
Recommendation: Funding agencies should establish funding structures for continued support for collaborative efforts of AMO theory and experiment with particle physics and other fields, including joint projects, joint summer schools, dedicated annual conferences, and so on.
Recommendation: U.S. federal agencies should establish mechanisms to co-fund international collaborations in precision searches for new physics with other worldwide funding agencies.
Finding: Other scientific fields, such as the life sciences, have tremendously benefited from AMO science and its tools, as highlighted by single-molecule
fluorescence microscopy and adaptive optics being used for super-resolution cellular imaging in near-native conditions. Subsequent advances in synthetic chemistry and materials science have dramatically improved the reach and impact of AMO science and its tools going beyond traditional AMO sciences. Yet, the cross-fertilization between AMO and other fields is not yet occurring at the highest speed possible because of lack of outreach in terms of awareness and availability of the new tools, techniques, and technologies.
Recommendation: Federal agencies should improve the availability and raise the awareness of the latest AMO technologies for researchers in other fields of science. Additionally, agencies should create funding opportunities to bridge the latest AMO technologies to other disciplines, specifically targeting early adopters.
Finding: Economic development results from AMO-related science and engineering. As exemplified by the University of Rochester, the University of Iowa, the University of Central Florida, the University of Arizona, and Montana State University, state-sponsored centers of excellence in AMO-inspired fields bring researchers and students together from different disciplines in universities, allowing state governments to make connections with industry and thereby promote workforce development. Students at universities benefit from direct exposure to a broader perspective for their coursework selections by direct exposure to what is needed for a career in research and development in industry. This also promotes interdisciplinary research at universities and enhances opportunities for external fundraising for faculty launching new interdisciplinary initiatives.
Recommendation: State governments should encourage the exploitation of opportunities to compete for economic development in AMO-related science and engineering user facilities at universities using state funding and/or industrial joint support.
Finding: The discussions of engineered quantum matter in Chapters 2 and 4 describe an important emerging field that brings together several disciplines of AMO physics to substantially increase the interaction between material and electromagnetic quantum states. There is great potential for a collaboration between scientists and industry on translational technologies that could miniaturize and scale up a wide range of laboratory-based quantum sensors, including optical clocks and frequency combs. This advance will require a significant increase in the availability of modern advanced photolithography for nanophotonic structures in Si and III-V materials. In addition, students in AMO would benefit greatly from centers dedicated to doctoral training in quantum
technologies, modeled on the Centres for Doctoral Training funded by the Engineering and Physical Sciences Research Council in the United Kingdom.
Recommendation: The National Science Foundation and Defense Advanced Research Projects Agency should create funding opportunities that target strong multidisciplinary collaboration between academia and industry to transfer current e-beam lithography methods in engineered quantum matter to advanced photolithography pilot lines.
Recommendation: The National Science Foundation Research Trainee Program should be expanded to ensure that the next generation of post-doctoral fellows are prepared to handle research and innovation challenges across the engineering and physical sciences landscape, particularly in quantum engineering.
Recommendation: The federal government should provide funding opportunities for basic research that enable the development of industrial platforms, such as foundry offerings, to support the integration of photonics and engineered quantum matter.
Finding: Astronomical observations have exposed significant shortcomings in our understanding of AMO science that will require significant scientific advances to address. In order to maximize the benefits of ground-based and satellite-based observations, new contributions from AMO theory and experiment are needed to classify the species observed and to understand in detail the elementary atomic and molecular processes occurring in astrophysical environments.
Recommendation: The National Science Foundation, Department of Energy, and National Aeronautics and Space Administration should support a strengthened community of faculty with the capability to carry out laboratory-based experiments, to develop theory, and to carry out computations in order to maximize the payoff from astrophysical observations and to encourage enhanced support from other funding agencies.
Finding: Funding trends for AMO sciences show, after correction for inflation, little to no increase over the past decade, even as the number of AMO scientists in the United States has grown.
Key Recommendation: The U.S. government should vigorously continue investment in curiosity-driven AMO science to enable exploration of a diverse set of scientific ideas and approaches. AMO is a critical investment in our economic and national security interests.
Finding: As AMO laboratory programs grow more expensive to seed, the need for seeding the research of early career investigators is increasingly important.
Recommendation: The federal government should develop seed funding and portable fellowship grant models that support the transition of atomic, molecular, and optical theorists and experimentalists into faculty positions.
Finding: The number of theoretical AMO faculty positions in the United States is perennially low (dangerously low in certain subfields of AMO). AMO theory is an important component of AMO science and presents U.S. scientists with an opportunity to contribute to a vibrant and exciting field.
Recommendation: A vibrant theory program needs to be incentivized through funding opportunities, such as a portable fellowship grant program, and through a sustained campaign of educating and hiring theoretical AMO physicists.
Finding: The participation of women in AMO science is alarmingly low, with a large gap (relative to white males) in education and career advancement opportunities and outcomes. Systemic barriers to larger participation include societal and institutional biases toward these groups—often unintentional but nonetheless impactful—that lead to already small numbers declining at each career stage. The cultural norms and practices are seen as creating unwelcoming workplaces for these groups.
Recommendation: Institutions receiving federal funding should implement stronger mechanisms to ensure a high standard of accountability in creating an inclusive workplace environment. Funding agencies may seek ways to incentivize this as well.
Finding: There is little data on underrepresented minorities, but from what we do have, it is clear that the numbers are even lower. The committee has requested data on representation of underrepresented minorities in federal funding and professional society membership, but very little information is available, in keeping with the very low numbers involved. Without high--
quality demographic data, the underrepresentation of certain groups continues to be relegated to guesstimation and conjecture. What we do know is that a tremendous opportunity to engage large swaths of American society in AMO science—and in all science, technology, engineering, and mathematics fields—is being squandered. The fraction of scientists in AMO from underrepresented minorities (URMs) is dramatically smaller than the fraction in the general public, making it clear that those benefiting from education and funding opportunities in AMO do not reflect the demographic shifts in the nation, and that is a lost opportunity for the entire field.
Recommendation: The entire AMO science enterprise should find a multitude of ways to tap into this growing talent pool.