Science Explorer Back to mapMap
Discussion
Topic · Atomic and Molecular Physics, and Optics

Advanced Frequency and Time Standards

Advanced Frequency and Time Standards is a research topic within Atomic and Molecular Physics, and Optics. Science Explorer counts 13k research works in it since 1950. 10.0% of them reached the world's top 10% most cited for their field and year.

This cluster of papers focuses on advancements in optical atomic clock technology, including frequency metrology, stability evaluation, and quantum metrology. It also explores applications in geodesy and the study of fundamental constants.

  • Optical Clocks
  • Atomic Clocks
  • Frequency Metrology
  • Lattice Clocks
  • Frequency Comparison
  • Stability Evaluation
  • Quantum Metrology
  • Frequency Transfer
  • Geodesy
  • Fundamental Constants
Research works
13k
fractional, since 1950
In the world top 10%
1.3k
per year above
Top-10% rate
10.0%
share of its works in the world top 10%
Growth, 2018-21 → 2022-25
+4%
the tick is no change
Largest producer
China
43% of the 10 largest, 2022-now
Advanced Frequency and Time Standards

Which countries lead Advanced Frequency and Time Standards research?

By volume, China and the United States publish the most (785 and 349 works in 2022-now).

By volume, 2022-now

  1. 1 China 785 works
  2. 2 United States 349 works
  3. 3 Germany 186 works
  4. 4 France 112 works
  5. 5 United Kingdom 84 works
  6. 6 Russia 82 works
  7. 7 Japan 72 works
  8. 8 India 71 works
  9. 9 Italy 55 works
  10. 10 Australia 39 works

How concentrated that is

The same countries as shares of everything the list above accounts for. A node where two countries do two thirds of the work and one spread evenly across twelve read alike as a ranking and not at all alike here.

China: 42.8%United States: 19.0%Germany: 10.1%France: 6.1%6 others listed: 22.0%43%largest
China785 · 42.8%United States349 · 19.0%Germany186 · 10.1%France112 · 6.1%6 others listed403 · 22.0%

Shares of the rows listed above, not of the whole node.

Which institutions lead Advanced Frequency and Time Standards research?

By volume in 2022-now, Chinese Academy of Sciences publishes the most Advanced Frequency and Time Standards research, followed by Centre National de la Recherche Scientifique and University of Chinese Academy of Sciences.

By volume, 2022-now

  1. 1 Chinese Academy of SciencesChina 152 works
  2. 2 Centre National de la Recherche ScientifiqueFrance 54 works
  3. 3 University of Chinese Academy of SciencesChina 46 works
  4. 4 Helmholtz Association of German Research CentresGermany 32 works
  5. 5 Peking UniversityChina 30 works
  6. 6 National University of Defense TechnologyChina 29 works
  7. 7 National Institute of Standards and TechnologyUnited States 29 works
  8. 8 Wuhan UniversityChina 27 works
  9. 9 University of Colorado BoulderUnited States 25 works
  10. 10 Russian Academy of SciencesRussia 25 works

Who are the leading researchers in Advanced Frequency and Time Standards?

The most-cited researchers publishing on Advanced Frequency and Time Standards include Kai You Wang, G. Mitselmakher and Yuichiro Yano.

  1. 1 Kai You Wang China 224k citations
  2. 2 G. Mitselmakher France 223k citations
  3. 3 Yuichiro Yano United States 203k citations
  4. 4 Ian W Harry Germany 189k citations
  5. 5 R. W. L. Jones United Kingdom 189k citations
  6. 6 Sanjit Mitra India 167k citations

Ranked by citations received across their whole record, among researchers with at least three works on this topic.

What are the most cited papers in Advanced Frequency and Time Standards?

The most cited paper in Advanced Frequency and Time Standards is "Bose-Einstein Condensation in a Gas of Sodium Atoms" (Kendall B. Davis, M.‐O. Mewes, Michael R. Andrews et al., 1995), with 5,629 citations. Next come "Advanced Virgo: a second-generation interferometric gravitational wave detector" (4,224) and "A two-solar-mass neutron star measured using Shapiro delay" (3,967).

Most cited papers
#PaperReleasedCitations
1 Bose-Einstein Condensation in a Gas of Sodium Atoms Kendall B. Davis, M.‐O. Mewes, Michael R. Andrews et al. · Physical Review Letters Open access 27 Nov 1995 5,629
2 Advanced Virgo: a second-generation interferometric gravitational wave detector F. Acernese et al. · Classical and Quantum Gravity Open access234 authors 18 Dec 2014 4,224
3 A two-solar-mass neutron star measured using Shapiro delay Paul B. Demorest, Timothy T. Pennucci, S. M. Ransom et al. · Nature Open access Oct 2010 3,967
4 Laser phase and frequency stabilization using an optical resonator Ronald W. P. Drever, J. L. Hall, Frank V. Kowalski et al. · Applied Physics B Jun 1983 3,831
5 Precise point positioning for the efficient and robust analysis of GPS data from large networks J. Zumberge, M. B. Heflin, David C. Jefferson et al. · Journal of Geophysical Research Atmospheres 10 Mar 1997 3,639
All 99 most cited papers, with filters and sorting

Where is Advanced Frequency and Time Standards research done?

The largest centres of Advanced Frequency and Time Standards research in 2022-now are Beijing (China), Wuhan (China), Shanghai (China) and Xi'an (China). Among places with at least 20 works in it, it is an unusually large share of all research in Gaithersburg, Braunschweig and Boulder.

Largest cities, 2022-now

  1. 1 BeijingChina 291 works
  2. 2 WuhanChina 88 works
  3. 3 ShanghaiChina 61 works
  4. 4 Xi'anChina 60 works
  5. 5 ParisFrance 56 works
  6. 6 MoscowRussia 39 works
  7. 7 ChangshaChina 38 works
  8. 8 HefeiChina 35 works
  9. 9 TokyoJapan 35 works
  10. 10 BoulderUnited States 31 works

Where it is the local speciality

  1. GaithersburgUS · 28.5 works68×
  2. BraunschweigDE · 21.0 works27×
  3. BoulderUS · 30.7 works22×
  4. PasadenaUS · 20.0 works21×
  5. HanoverDE · 21.4 works13×
← less than its size predicts1×more →

Location quotient: how much more of its research is in Advanced Frequency and Time Standards than the world average.

See Advanced Frequency and Time Standards on the map

Where is the best place to study Advanced Frequency and Time Standards?

Among universities, judged by research, University of Colorado Boulder, Beihang University and University of Chinese Academy of Sciences score highest, combining excellence, specialisation, size, growth and international reach. Research strength is one signal when choosing where to study; it does not measure teaching.

0%20%40%mean 16.93%fractional works in this field (log) →share of work in the world top 10% →University of Colora…Beihang UniversityWuhan UniversityUniversity of Chines…
above the meannear itbelow it

One dot per university in the first ten of the table below, at the default weights. The upper left is the interesting corner: small places doing unusually strong work.

Excellenceshare of its work in the world top 10%, 2022-now and all time averaged
40%
Specialisationhow much of its work is in this field, counted up to 10× the world share
10%
Sizeits output in this field, on a log scale
30%
Growthoutput growth, counted from -20% to +20%
10%
Internationalshare of its work with a co-author abroad
10%
Each slider sets a weight; the share it gets of the score is beside it.
#UniversityScoreTop 10%SpecialisationWorksGrowth
1University of Colorado BoulderUnited States 82.028.6%29.9×26 +0.1%
2Beihang UniversityChina 64.421.6%11.4×24 +15.5%
3University of Chinese Academy of SciencesChina 64.310.0%15.2×46 +18.1%
4Wuhan UniversityChina 60.817.8%10.4×27 -14.5%
5Peking UniversityChina 58.413.1%7.8×30 +44.7%
6Leibniz University HannoverGermany 55.613.0%35.9×20 -13.4%
7Hefei UniversityChina 54.120.9%63.1×12 -
8California Institute of TechnologyUnited States 53.714.6%28.3×19 -6.2%
9National University of Defense TechnologyChina 50.812.7%20.3×29 +32.4%
10University of Science and Technology of ChinaChina 49.517.0%6.5×14 +163.9%

Universities only. The score blends excellence (40%), size (30%), specialisation (10%), growth (10%), international reach (10%), 2022-now; growth compares 2018-21 with 2022-25 and counts up to +20%, since a jump from a small base is mostly noise.

Every institution in Advanced Frequency and Time Standards, country by country

Is Advanced Frequency and Time Standards research growing?

Output in 2022-2025 was 4% higher than in 2018-2021, peaking in 2025. The fastest-growing topics are Advanced Frequency and Time Standards.

still counting19801990200020102020
grewheldshrank

The same series as a ribbon: one cell per year, darker for more. The line above answers how much; this answers when.

Its share of all research

Growing output can still be a shrinking share: all of science grows. This is Advanced Frequency and Time Standards as a percentage of every work published that year, 0.0079% in 2024.

still counting0.010%0.020%0.030%Advanced Frequency and Time Standards0.0090% in 202519801990200020102020

Fractional works of Advanced Frequency and Time Standards over all fractional works that year. How the balance of science has shifted.

How much of it reaches the world top 10%

Year by year.

still counting5%10%15%Advanced Frequency and Time Standards9.7% in 2025200020102020

Of each year's works in it, the share that reached the world's 10% most cited for their field and year. A field is the world for its own topics, so there is no other line to hold it against.

Which topics inside it are moving

Growth and decline on one axis around a shared zero. Two lists side by side hide the thing that matters: whether the growth dwarfs the decline, or the other way round.

Discussion

Ask a question or share a note about Advanced Frequency and Time Standards. Posts are plain text and can be reported.