Broadband and efficient Quantum Memory Using ac Stark Gradient Echo Memory

TL;DR

This paper proposes a room-temperature quantum memory technique called ac Stark Gradient Echo Memory (ASGEM) that achieves high efficiency and large bandwidth by using a virtual magnetic field created via the ac Stark effect, enabling GHz bandwidth photon storage with over 90% efficiency.

Contribution

It introduces the ASGEM method that combines high efficiency and broad bandwidth in quantum memory using ac Stark effect in atomic vapor, with detailed simulation for optimization.

Findings

Achieves over 90% storage and retrieval efficiency.

Enables photon storage with about 1 GHz bandwidth.

Uses a far-detuned nanosecond ac Stark pulse at 127 THz.

Abstract

A quantum state light-storage, using a virtual magnetic field through the ac Stark effect is proposed to combine the high overall storage efficiency and large bandwidth employing room temperature atomic vapor. In this approach, which was called the ac Stark Gradient Echo Memory (ASGEM), it has been shown the possibility to employ about a nanosecond ac Stark pulse far detuned (about 127 THz) from D1 line of rubidium and create an atomic media with the possibility to store a photon with about a GHz bandwidth with storage and retrieval efficiency of more than 90%. A contour plot of efficiency as a function of gradient field strength and optical depth, based on three-level Maxwell- Bloch equations, simulated for a better understanding of experimental parameter optimization.