A Clock Directly Linking Time to a Particle's Mass

Abstract

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 ω(0) = mc(2)/[formula: see text] where c is the speed of light and [formula: see text] is Planck's constant h divided by 2π. A clock referenced to ω(0) 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 ω(0.) 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.

High-Resolution Atom Interferometers with Suppressed Diffraction Phases

“…Using multiphoton Bragg diffraction [4,5] and simultaneous operation of conjugate interferometers [6], the phase difference has been increased to Φ = 16n 2 ω r T (where the factor of 16 arises from taking the phase difference of the two interferometers), and Earth's gravity and vibrations have been canceled. Unfortunately, however, Bragg diffraction causes a diffraction phase [2, 7-9], which has been the largest systematic effect in high-sensitivity atom interferometers using this technique [2]. Here, we study the diffraction phase in detail and show that it can be suppressed and even nulled by introducing Bloch oscillations as shown in Fig.…”

Coherent Stern–Gerlach momentum splitting on an atom chip

“…T he development of atom interferometry over the last two decades has given rise to new insights into the tenets of quantum mechanics 1 as well as to ultra-high accuracy sensors for fundamental physics [2][3][4] and technological applications 5,6 . Examples range from the creation of momentum state superpositions by accurate momentum transfer of laser photons 7,8 allowing high precision measurements of rotation, acceleration and gravity 5,6,9,10 , to the splitting of trapped ultracold atoms by local potential barriers [11][12][13] allowing the investigation of fundamental properties of quantum systems of a few or many particles, such as decoherence and entanglement [14][15][16] .…”

Gravity without Newton's Gravitational Constant and No Knowledge of Mass Size

“…This may sound absurd at first, as the Planck mass is so much larger than any known particle. However, recent research has indicated that mass at a deeper level can be seen as a Compton clock [26,27]. This suggests that the Planck mass is related to the Planck time [28], and instead of looking for a very large mass (compared to any observed particle), we should be looking for a very small mass, approximately 1.17 × 10 −51 kg.…”