An Assessment of the National Institute of Standards and Technology Physical Measurement Laboratory: Fiscal Year 2025 (2026)
Chapter: 5 Quantum Measurement
5
Quantum Measurement
BACKGROUND ON THE QUANTUM MEASUREMENT DIVISION
The Quantum Measurement Division (QMD) provides foundational metrological infrastructure for the United States, with a particular emphasis on the International System of Units (SI) realization, the SI dissemination, and quantum science. As part of this work, the QMD realizes and supports several SI units, provides calibration services, conducts research into atomic and quantum physics, and innovates new measurement methods and quantum-based technologies. The division is organized into groups on Atomic Spectroscopy (not covered in this assessment as it is slated for closure), Quantum Optics, Laser Cooling and Trapping, Fundamental Electrical Measurements, Applied Electrical Metrology, and Mass and Force. This division also collaborates with the University of Maryland through the Joint Quantum Institute to advance quantum science in areas such as quantum computation and simulation.
The breadth of the division is demonstrated in its leadership in quantum science, its pioneering techniques in mass and force, and its participation in national policy across the federal government. Its impacts are demonstrated in the number of publications, Cooperative Research and Development Agreements (CRADAs), and patents and licenses generated by the division as well as the QMD staff’s participation in global documentary standards committees. The QMD undertakes about 77 types of calibrations, with 5,502 calibration tests performed over the past 4 years totaling $6.4 million. The division had a total of 265 publications across 87 journals with 346 co-author affiliations, and its papers had 3,099 citations since 2021 at the time of the assessment. Its technology transfer metrics included 5 CRADAs, 61 invention disclosures, 43 patents (13 granted, 30 pending), and 6 licenses in the past 4 years. At the time of this assessment, the QMD employed approximately 100 employees, of which approximately half were federal employees and half were associates.1 In fiscal year 2025, QMD had a budget of $33.29 million, of which $26.74 million were scientific and technical research services funds, $4.12 million were other agency funds and $2.01 million were Measurement Services funds, and $437,800 were Creating Helpful Incentives to Produce Semiconductors (CHIPS) and Science Act funds2 (PML 2025).
___________________
1 Associates are domestic and foreign guest researchers from academia, industry, and other government agencies who collaborate on NIST research projects and use NIST facilities but are not NIST employees.
2 Other agency funds are funding of NIST projects from other government agencies. Working capital funds include external reimbursable activity such as calibrations and internal reimbursable activity such as calibration operations and service development and standard reference material production and service development.
TECHNICAL PROGRAMS
The QMD’s accomplishments cover a wide spectrum. The Laser Cooling and Trapping Group (LCTG) broadly explores science at the intersection of atomic, molecular, and optical physics, condensed-matter physics, and quantum information science, using both experimental and theoretical approaches. This group includes some of the most prominent research teams in the world, pioneering techniques of laser cooling and their application to various problems in metrology. Additionally, they have further expanded into areas of quantum simulation. The combination of expertise and the resulting expansion has allowed them to define a new and active subfield with transformational effects on our understanding of quantum systems: large and small, in and out of equilibrium, open and closed. A substantial portion of this division’s work, done in collaboration with researchers through the Joint Quantum Institute and the University of Maryland, leads to a dynamic research environment and culture, combining traditional strengths of academia with those of a federal laboratory. The success of this group is clearly evidenced by a robust and high-impact publication record, placement of early-career staff into prominent positions in academia, government, and industry, and awards and accolades of many members of the group ranging from high-school interns to a Nobel Prize winner (and reflecting a characteristic “full-spectrum” commitment to excellence and mentorship in the group). Multiple high-value U.S. companies have been launched utilizing technical breakthroughs developed in part by this group.
Compelling ongoing research in this group includes inquiries of critical industrial significance, most prominently for quantum computing, communication, and sensing, specifically on weak measurement of quantum degenerate gases, autonomous cooling of qubits, and engineered Rydberg interactions in cold atoms. These studies are timely, and track tightly with critical technology development of national and worldwide significance, providing insight into important phenomena that crosscut many competing approaches aggressively developed for quantum technologies by industry and other sectors.
The Quantum Optics Group is leading the single-photon-sources development for quantum networks. The dictionary for single-photon sources and detectors, first published in 2023 and then revised in 2025, is an important first step in standardization for the quantum community. The report, an outcome of a National Institute of Standards and Technology (NIST)-led Quantum Economics Consortium workshop, is an excellent example of response to stakeholder needs. The group is an active participant in the Washington Metropolitan Quantum Network Research Consortium, a network testbed to evaluate components and protocols. Efforts in quantum network development include demonstrating coexistence of quantum and classical signals, subpicosecond timing synchronization, and next-generation telecommunication-compatible single-photon sources.
As described in the 2021 National Academies report, a notable accomplishment of the Fundamental Electrical Measurement Group has been the development of the Kibble balance for the primary realization of mass (NASEM 2021). The impressive work of the group has led to the redefinition of the kilogram in terms of the Planck constant. The official SI redefinition on May 20, 2021, is noted along with the ongoing use of the consensus value arising from disagreement between the two leading measurements (the Avogadro project at Physikalisch-Technische Bundesanstalt, Germany, and the Kibble balance at the National Research Council-Canada). With the NIST-4 Kibble balance, measurement of the Planck constant and subsequent realization of the kilogram are carried out with remarkable accuracy (<10 ppb) once evaluation of the different magnetic coils is complete, currently comparable to other world leaders in this sector (Haddad 2025). Ongoing collaborations are under way with the Physikalisch-Technische Bundesanstalt in Germany and the Research Institutes of Sweden (RISE) to compare measurement of standards at different institutes and decrease uncertainty. In the collaboration with the Research Institutes of Sweden, PML demonstrated the quantum metrology triangle through the implementation of the quantum Hall resistance array in the measurement circuit of their Kibble balance. Since the 2021 National Academies review, QMD has made laudable progress in establishing the Quantum Electro-Mechanical Metrology Suite. The group also leveraged a nascent CRADA with industry to deploy small-scale calibration systems (versions of KIBB-g2 and subsequent revisions). Based on the Kibble balance, PML is successfully establishing and transitioning table-top standards for mass and torque to industry (e.g., Snap-on) and the Department of Defense establishments (e.g., U.S. Army TMDE Activity (USATA) Primary Calibration Laboratory at Redstone Arsenal, Nellis Air Force Base). There is also a growing portfolio of PML patents filed stemming from this division’s work.
Overall, this transition work has been outstanding and has tremendous potential for impact, which is expected to see further growth in the future.
The Applied Electrical Metrology Group (AEMG) performs foundational research to create deployable, multifunction quantum electrical standards. They aim to improve the dissemination of SI by creating tools and techniques that increase the efficiency and user-friendliness of quantum standards. The group supports the nation through calibrations of alternating current (AC) voltage and direct current (DC) voltage, AC current ratio, as well as AC-DC difference, electric power, and phase angle. The AEMG has a strong technical program that meets its objectives and is competitive with other National Metrology Institutes’ (NMIs’) research. The group is working on a unified quantum electrical realization to combine the quantum Hall resistor with a Josephson voltage standard to provide direct traceability for Ohm’s law in one system. The significant impact of this work will be extremely beneficial for primary standards laboratories throughout the nation, lauded in press coverage as a “one box” electrical standard that is more deployable and less complex (Underwood et al. 2025). The group is focusing on improving the user’s experience for the Josephson Arbitrary Waveform Synthesizer to improve automation of optimization of the system. The group is developing a new nanophotonic thermal transfer device that aims to reduce the uncertainties for AC-DC difference through accurate comparison of AC and DC joule heating.
Technical contributions within the Mass and Force Group display an excellent combination of core calibration services in conjunction with the metrological scientific advances. This group works closely with the Fundamental Electrical Measurement Group to take the realization of the kilogram from the Kibble balance and disseminate that throughout their world-leading mass and force capabilities spanning more than 14 orders of magnitude (e.g., 10 micronewton resolution for the electrostatic force balance to meganewtons in the million pounds-force deadweight machine). Exemplifying one of the numerous pioneering measurement techniques conceived and fabricated within the Mass and Force Group is the refractive index sound standard, which enables a direct calibration of microphones across a variety of acoustic devices, instead of the traditional comparison method that is only as good as the reference microphone. Microphones are key in nuclear testing, sound-level safety analysis for work sites, and more.
SCIENTIFIC EXPERTISE
The different groups have the appropriate level of scientific and engineering staff to deliver on their mission. In particular, the technical caliber of the QMD staff, associates, and visiting scientists is excellent. Many of the staff members received one or more prestigious awards during their service, with examples being the NIST Gold Medal and PML Distinguished Associate Awards. Junior staff members have also received multiple early-career scientist awards and have been awarded multiple fellow appointments with various organizations.
Over the past several years, members of the QMD routinely made substantial, and even essential, contributions to national policy leadership and direction through details in the Office of Science and Technology Policy and the National Science Foundation, representing an important contribution of the group. After recent changes at the federal level, this share of voice has been diminished; the QMD should strive to continue its tradition of serving as a resource within new and emerging national science initiatives and policies.
The LCTG currently has five principal leaders, all of whom are recognized worldwide as top contributors to their field of laser-cooled atomic gases and together bring expertise across the group’s mission and program objectives, including one Nobel laureate and prominent members of national science policy organizations. Two recent departures of senior leaders have resulted in gaps in expertise, and a significantly improved outlook for future work could be ensured by high-level recruitment in quantum optics and single- or few-atom quantum control scientists to replace these competencies and react to the emerging interests within U.S. industry.
Similar to the LCTG, departures of key members of the Mass and Force Group have the potential to jeopardize the turnaround time and quality of mass and force calibrations routinely utilized by U.S. industry and other government laboratories, and full participation on the national stage with other NMIs. Compounding the above issue, key members are reaching retirement age, which makes succession planning even more critical. Departure of further staff in this area could require replacing missing capabilities needed to maintain the necessary quality and throughput. Bolstering the calibration side of this group with one or two early-to-mid-career scientists would ameliorate negative consequences of departures within the group over the next decade.
FACILITIES, EQUIPMENT, AND HUMAN RESOURCES
The QMD has demonstrated remarkable research and calibration output since the last review in 2021, despite facing significant challenges in 2025 owing to hiring freezes and anticipated decreases in future funding. These resource constraints jeopardize the operation of aging facilities, which are crucial for maintaining the division’s high standards.
Unique facilities, such as the Quantum Electro-Mechanical Metrology Suite that houses the Kibble balance, benefit from the dedication of laboratory staff who work diligently to minimize downtime. For instance, due to HVAC malfunctions, NIST staff often come in during off hours to perform calibrations when environmental conditions meet the necessary specifications for temperature and relative humidity. However, NIST calibration services are increasingly struggling to compete on cost with other NMIs that may benefit from additional government subsidies, allowing them to offer lower prices. Currently, the staff levels are at a minimum required to maintain the existing calibration workload, which hampers efforts to enhance services and advance scientific research.
The AEMG possesses strong expertise but has faced numerous retirements in recent years without successfully backfilling those positions. With only four staff members currently, it is essential to recruit additional personnel to support the group’s mission effectively. As noted in the 2021 report, the group lacks sufficient staffing to meet calibration demands and to provide multijunction thermal converter standard reference instruments to its customer base (NASEM 2021). While the equipment is adequate for the organization’s missions, persistent facility issues, such as problems with processed chilled water and electromagnetic interference, often lead to measurement inaccuracies and instrument downtime.
Facilities for the LCTG and Quantum Optics Group, built in 2006, represent some of the most recent infrastructural investments on the Gaithersburg campus. Although the laboratories are reasonably modern and well designed, the core performance of the building envelope does not align with its age, and environmental control systems frequently fail, limiting productivity. Moderate investments in building improvements, compared to other groups in the division, are likely warranted and could yield significant returns through increased calibration and experimental uptime.
Considering these challenges, the QMD has made the difficult decision to retire the Atomic Spectroscopy Group this year. Additionally, backfilling aging staff in precision metrology remains a challenge, as this specialized work requires 4–5 years of training. The division plans to rely on PML’s succession planning budget as needed, although it may not be sufficient to meet the long-term needs of these critical groups.
EFFECTIVENESS OF DISSEMINATION OF PROGRAM OUTPUTS
Dissemination of outputs is a key priority for the division. The methods include physical media and instrumentation transfer, publications in peer-reviewed journals and conference presentations, patent applications, software for facilitating operation of instrumentation and data analysis, as well as various databases.
The QMD has published 265 publications over the past 4 years in journals such as Physical Review Letters, Physical Review A, and PRX Quantum. They generated 5 CRADAs with different companies, 43 patents (13 granted, 30 pending), and 6 licenses. They performed 5,502 customer calibrations which have had a significant impact for the nation, with one example being approximately 6 calibrations per year at NIST transforming into more than 300,000 calibrations performed by the state metrology laboratories every year (NCSLI 2024). Approximately one-third of the QMD’s staff serve on or lead documentary standards committees, which have a significant impact on the global metrology community. These documentary standards range from applied metrology via the International Measurement Confederation (IMEKO) to the International Atomic Energy Agency, which is the leading cooperative platform for nuclear applications such as energy and medicine.
Other revolutionary approaches to dissemination of the SI stem from the development of the electrostatic force balance (EFB), which utilizes the same principles as the Kibble balance but operates in a completely different mass and force regime (submilligram and submicronewton). In addition to the obvious application to mass and force calibrations, such as achieving a 10-fold improvement in uncertainty for 1 mg calibrations, the advancement has enabled ongoing work toward providing mass references for micrometer-sized particles containing rare earth
or transition metal elements necessary to create 21st century electronics. The scientific creativity and rigor of the EFB team extended its application to numerous nonobvious, yet essential, areas such as the calibration of atomic force microscopy (AFM) cantilevers that are ubiquitous for characterization of new materials and realization of the optical watt via in situ measurement from a mirror attached to the EFB. As noted in the 2021 review as well, the establishment of the Quantum SI, and in particular the introduction of the new mass standard in terms of the Planck constant, has been accompanied by an outstanding range of outreach and educational activities, including in particular the NIST do-it-yourself LEGO® Kibble balance, which permits a broad audience of students and science enthusiasts to build their own working Kibble balances out of LEGO® bricks. Staff from QMD created productive engagements with industry and the U.S. Department of War (DOW), which led to wider use of the table-top Kibble balance for both mass and torque measurements.
With the closure of the Atomic Spectroscopy Group, the web-based databases of spectral lines, energy levels of atoms and ions, ionization energies, and an extensive bibliography of the sources are no longer updated. These resources are instrumental for research in atomic physics and spectroscopy conducted by major stakeholders: Department of Energy and DOW laboratories, the National Aeronautics and Space Administration, academia, and industry. It is of paramount importance for NIST to maintain close collaboration with the Joint Quantum Institute to continue providing access to these atomic data. However, recent advances in several areas of research require extending the range of available data, with a few examples needed for EUV lithography targets being gadolinium, bismuth, and other high-Z elements which often have complex electron energy level structures. The ability to benchmark ab initio calculations and atomic simulations against accurate, validated sets of data is extremely valuable. Existing databases, however, do not contain the data for relevant ionization stages. Updated databases would provide crucial information for the development of the radiation sources and optical components helping to maintain U.S. leadership in the semiconductor business.
CONCLUSIONS AND RECOMMENDATIONS
Conclusion 5-1: The Quantum Measurement Division demonstrates world-class calibration and research capabilities. It is critical to the core National Institute of Standards and Technology (NIST) mission of realizing and disseminating the International System of Units (mass, force, ampere), which underpins nearly every commercial product in the United States. The teams actively engage with international counterpart National Metrology Institutes to seek consensus and improve NIST’s state-of-the-art calibration systems, while working with partners to adapt these systems for wider adoption. While the equipment is adequate for the organization’s missions, persistent facility issues, such as problems with processed chilled water and electromagnetic interference, often lead to measurement inaccuracies.
Recommendation 5-1: The National Institute of Standards and Technology (NIST) Physical Measurement Laboratory should collaborate with the Quantum Measurement Division and NIST leadership, and the Office of Facilities and Property Management to continue to pursue facilities upgrades from deferred maintenance (e.g., flood prevention, better humidity control), as the ongoing facility issues drastically impact calibration turnaround times and equipment uptime. The Quantum Measurement Division should consider expanding its use of dedicated technical staff (currently a single engineer who interfaces with the NIST facilities group) to maintain its specialized facilities needed for calibration of equipment and groundbreaking research.
Conclusion 5-2: Quantum Measurement Division staff provide critical voices for defining the country’s national quantum initiative strategy and continually generate excellent research in the field of quantum simulation, quantum thermodynamics, and single-photon sources. As the quantum science and technology ecosystem grows, clarifying the National Institute of Standards and Technology’s role in the next 5 years will become more important.
Recommendation 5-2: The Quantum Measurement Division (QMD) leadership should create a communication plan with clear industry-relevant metrics that shows how its research and calibrations have positively impacted U.S. commerce. Such a proactive initiative should spearhead further engagement with industry to identify emerging needs in standards and metrology and enable collaborative updates to existing databases and reports. The leadership of the Physical Measurement Laboratory and the QMD should ensure that valuable databases, such as the one assembled and maintained by the former Atomic Spectroscopy Group, are retained and remain available to government and industrial entities.
Conclusion 5-3: The Quantum Measurement Division (QMD) exhibits high engagement with academic collaborators, especially with the University of Maryland through the Joint Quantum Institute. High-profile publications, especially in metrology, show the continued relevance and quality of the research. In 2025, the QMD lost significant senior staff, both through incentivized early retirement and through transfer to other parts of government. The combination of the Physical Measurement Laboratory’s succession planning fund, reinstatement of the National Research Council postdoctoral program, and its plan to backfill currently open positions is critical for maintaining the current level of success at producing scientific achievements needed to enable the precision calibration services the National Institute of Standards and Technology provides that underlie the U.S. economy.
Recommendation 5-3: The Quantum Measurement Division (QMD) should collaborate with other Physical Measurement Laboratory divisions (in both Gaithersburg and Boulder) to formulate a unified strategic approach in quantum technologies (communication, sensing, and computation) and identify a select set of distinctive capabilities that leverage their unique metrology expertise. The QMD should prioritize activities both within and beyond its current expertise, identifying underrepresented areas and organizational weaknesses in critical national technologies, and articulating pathways to address these gaps, including redistribution of efforts between divisions.
REFERENCES
EUV Litho. n.d. “Blue – X.” EUV Litho, Inc. https://euvlitho.com/blue-x. Accessed December 19, 2025.
Haddad, D. 2025. “NIST Primary Realization of Mass via Kibble Balances.” Presentation to the committee. September 9. Gaithersburg, MD.
NASEM (National Academies of Sciences, Engineering, and Medicine). 2021. An Assessment of Selected Divisions of the Physical Measurement Laboratory at the National Institute of Standards and Technology: Fiscal Year 2021. Washington, DC: National Academies Press. https://doi.org/10.17226/26312.
NCSLI (National Conference of Standards Laboratories International). 2024. State Laboratory Program Workload Survey. NCSLI 156 Legal Metrology Committee. https://www.nist.gov/system/files/documents/2025/06/17/2024%20SLP%20Workload%20Survey.pdf
PML (Physical Measurement Laboratory). 2025. Read-Ahead Material for NASEM Assessment of PML. National Institute of Standards and Technology, Gaithersburg, MD. Including updated actual obligated budget figures from Gerald Fraser, National Institute of Standards and Technology, March 25, 2026.
Underwood, J., B. Waltrip, and Z. Barcikowski. 2025. “Quantum Waveform Metrology.” National Institute of Standards and Technology. https://www.nist.gov/programs-projects/quantum-waveform-metrology.
