Transverse Mode Revival of a Light-Compensated Quantum Memory

TL;DR

This paper reports a significant enhancement in the lifetime of a cold atom quantum memory using light compensation, and observes transverse mode oscillations that inform decoherence understanding.

Contribution

It introduces a method to extend quantum memory lifetime by 40 times using a compensation laser and clarifies the role of transverse mode breathing in efficiency oscillations.

Findings

Memory lifetime increased from 0.67 ms to 28 ms

Oscillations in efficiency due to transverse mode breathing observed

Provides a benchmark for high-quality quantum memory development

Abstract

A long-lived quantum memory was developed based on light-compensated cold $^{87}$Rb atoms in a dipole trap. The lifetime of the quantum memory was improved by 40 folds, from 0.67 ms to 28 ms with the help of a compensation laser beam. Oscillations of the memory efficiency due to the transverse mode breathing of the singly-excited spin wave have been clearly observed and clarified with a Monte-Carlo simulation procedure. With detailed analysis of the decoherence processes of the spin wave in cold atomic ensembles, this experiment provides a benchmark for the further development of high-quality quantum memories.