Symmetry protected single photon subradiance

TL;DR

This paper investigates how symmetry in atomic arrangements can protect subradiant states, enhancing quantum memory stability by exploiting reflection and continuous symmetries to achieve long-lived photon states.

Contribution

It demonstrates that symmetry considerations can be used to protect subradiant states in the Dicke limit, including reflection and continuous symmetries, advancing quantum memory applications.

Findings

Anti-symmetric states are subradiant with reflection symmetry.

Continuous symmetry can also induce subradiance.

Symmetry-based protection enhances quantum memory robustness.

Abstract

We study the protection of subradiant states by the symmetry of the atomic distributions in the Dicke limit, in which collective Lamb shifts cannot be neglected. We find that anti-symmetric states are subradiant states for distributions with reflection symmetry. Continuous symmetry can also be used to achieve subradiance. This study is relevant to the problem of robust quantum memory with long storage time and fast readout.