摘要
Historically, time measurements have been based on oscillation frequencies in systems of particles, from the motion of celestial bodies to atomic transitions. Relativity and quantum mechanics show that even a single particle of mass m determines a Compton frequency ω0 = mc 2/ℏ, where c is the speed of light and ℏ is Planck's constant h divided by 2π. A clock referenced to ω0 would enable high-precision mass measurements and a fundamental definition of the second. We demonstrate such a clock using an optical frequency comb to self-reference a Ramsey-Bordé atom interferometer and synchronize an oscillator at a subharmonic of ω0. This directly demonstrates the connection between time and mass. It allows measurement of microscopic masses with 4 × 10-9 accuracy in the proposed revision to SI units. Together with the Avogadro project, it yields calibrated kilograms.
原文 | English |
---|---|
頁(從 - 到) | 554-557 |
頁數 | 4 |
期刊 | Science |
卷 | 339 |
發行號 | 6119 |
DOIs | |
出版狀態 | Published - 2013 二月 1 |
All Science Journal Classification (ASJC) codes
- General