Atom-light-correlated quantum interferometer with memory-induced phase comb

TL;DR

This paper introduces a novel atom-light hybrid quantum interferometer that surpasses the standard quantum limit by leveraging atom-light correlations and atomic memory, achieving unprecedented phase sensitivity for precise measurements.

Contribution

It presents a new method combining atomic memory and quantum amplification to enhance phase sensitivity beyond the SQL in atom-light interferometry.

Findings

Achieved phase sensitivity beyond SQL by up to 8.3 dB.

Demonstrated atomic and optical phase sensitivities of 6×10⁻⁸ rad/√Hz.

Implemented phase comb superposition with atomic memory for quantum amplification.

Abstract

Precise phase measurements by interferometers are crucial in science for detecting subtle changes, such as gravitational waves. However, phase sensitivity is typically limited by the standard quantum limit (SQL) with uncorrelated particles N. This limit can be surpassed using quantum correlations, but achieving high-quality correlations in large systems is challenging. Here, we propose and demonstrate an atom-light hybrid quantum interferometry whose sensitivity is enhanced beyond the SQL with atom-light quantum correlation and newly developed phase comb superposition via atomic-memory-assisted multiple quantum amplification. Finally, a phase sensitivity beyond the SQL of up to $8.3\pm 0.2$ dB is achieved, especially at $N=4 \times10^{13}/s$, resulting in both atomic and optical phase sensitivities of $6\times10^{-8} rad/\sqrt{Hz}$. This technique can advance sensitive quantum measurements in various fields.