Bose-Einstein condensate as a quantum memory for a photonic polarization qubit

TL;DR

This paper demonstrates a high-fidelity method for storing photonic polarization qubits in a Bose-Einstein condensate using electromagnetically induced transparency, achieving long storage times and efficient retrieval.

Contribution

It introduces a novel scheme for quantum memory that preserves polarization qubits in a BEC with optimized fidelity and efficiency.

Findings

Average process fidelity of 1.000 +/- 0.004

Fidelity lifetime of 1.1 +/- 0.2 ms

Write-read efficiency of 0.53 +/- 0.05

Abstract

A scheme based on electromagnetically induced transparency is used to store light in a Bose-Einstein condensate. In this process, a photonic polarization qubit is stored in atomic Zeeman states. The performance of the storage process is characterized and optimized. The average process fidelity is 1.000 +/- 0.004. For long storage times, temporal fluctuations of the magnetic field reduce this value, yielding a lifetime of the fidelity of 1.1 +/- 0.2 ms. The write-read efficiency of the pulse energy can reach 0.53 +/- 0.05.