de-Broglie Wavelength Enhanced Weak Equivalence Principle Test for Atoms in Different Hyperfine States

TL;DR

This paper presents a novel atom interferometry experiment using de-Broglie wavelength enhancement to test the weak equivalence principle with different hyperfine states of rubidium atoms, achieving improved sensitivity.

Contribution

It introduces a new WEP test method leveraging de-Broglie wavelength enhancement and hyperfine state manipulation in a single atom interferometer, surpassing previous bounds.

Findings

WEP violation bound improved to 2.9×10⁻¹¹

Utilizes de-Broglie wavelength to enhance test sensitivity

Achieves one order of magnitude better limit than prior work

Abstract

We report a hyperfine-states related weak equivalence principle (WEP) test which searches for possible WEP violation signal in single atom interferometer. With the ground hyperfine states $\left|F=1\right\rangle$ and $\left|F=2\right\rangle$ of $^{87}$Rb atoms simultaneously scanned over different paths in a Raman Mach-Zehnder interferometer (MZI), the difference of the free fall accelerations for the atom in the two hyperfine states is encoded into the phase shift of the MZI, contributing a WEP test signal. The test signal can be extracted out by reversing the direction of the effective wave vector of the Raman laser to suppress direction-dependent disturbances. More importantly, de-Broglie wavelength of cold atoms can be utilized to enhance the test signal in our scheme, which helps to improve the upper bound of the WEP test for atoms in different hyperfine states to $2.9\times10^{-11}$, about one order of magnitude lower than the previous record.