All optical quantum storage based on spatial chirp of the control field

TL;DR

This paper proposes an all-optical quantum memory scheme utilizing spatial chirp in the control field, enabling reversible inhomogeneous broadening without external field modulation, suitable for materials lacking Stark or Zeeman effects.

Contribution

The scheme introduces a novel method for quantum storage using spatial chirp, avoiding the need for temporal control or external fields, expanding material applicability.

Findings

The spatial chirp acts as a controllable reversible inhomogeneous broadening.

The scheme does not require external electric or magnetic fields.

It can be implemented in materials without Stark or Zeeman effects.

Abstract

We suggest an all-optical quantum memory scheme which is based on the off-resonant Raman interaction of a signal quantum field and a strong control field in a three-level atomic medium in the case, when the control field has a spatially varying frequency across the beam, called a spatial chirp. We show that the effect of such a spatial chirp is analogous to the effect of a controllable reversible inhomogeneous broadening (CRIB) of the atomic transition used in the gradient echo memory (GEM) scheme. However, the proposed scheme does not require temporal modulation of the control field or the atomic levels, and can be realized without additional electric or magnetic fields. It means that materials demonstrating neither linear Stark nor Zeeman effects can be used and/or materials which are placed in specific external fields remain undisturbed.