Quantum-Enhanced Velocimetry with Doppler-Broadened Atomic Vapor

Abstract

Traditionally, measuring the center-of-mass (c.m.) velocity of an atomic ensemble relies on measuring the Doppler shift of the absorption spectrum of single atoms in the ensemble. Mapping out the velocity distribution of the ensemble is indispensable when determining the c.m. velocity using this technique. As a result, highly sensitive measurements require preparation of an ensemble with a narrow Doppler width. Here, we use a dispersive measurement of light passing through a moving room temperature atomic vapor cell to determine the velocity of the cell in a single shot with a short-term sensitivity of 5.5 $\mu$m s${}^{-1}$ Hz${}^{-1/2}$. The dispersion of the medium is enhanced by creating quantum interference through an auxiliary transition for the probe light under electromagnetically induced transparency condition. In contrast to measurement of single atoms, this method is based on the collective motion of atoms and can sense the c.m. velocity of an ensemble without knowing its velocity distribution. Our results improve the previous measurements by 3 orders of magnitude and can be used to design a compact motional sensor based on thermal atoms.

References in corpus (13)

• Optical Magnetometry
• Atom Interferometers
• Measurement of the fine-structure constant as a test of the Standard Model
• Precision Measurement of the Newtonian Gravitational Constant Using Cold Atoms
• Quantum Test of the Universality of Free Fall
• Test of Equivalence Principle at $10^{-8}$ Level by a Dual-species Double-diffraction Raman Atom Interferometer
• Matter wave lensing to picokelvin temperatures
• Light storage for one second at room temperature
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Cited by in corpus (4)

• Optomechanical resonator-enhanced atom interferometry
• Thermal resonance-enhanced transparency in room temperature Rydberg gases
• Controlled Displacement of Stored Light at Room Temperature
• Homodyne detection of a two-photon resonance assisted by cooperative emission