Ultrafast quantum random access memory utilizing single Rydberg atoms in a Bose-Einstein condensate

TL;DR

This paper introduces a quantum memory system using Rydberg atoms in a Bose-Einstein condensate that allows for ultrafast, high-fidelity quantum information transfer within approximately 10 nanoseconds, significantly surpassing flux qubit lifetimes.

Contribution

The work demonstrates a novel quantum memory architecture enabling rapid, high-fidelity qubit transfer using Rydberg atoms in a BEC, with potential for high cycle rates.

Findings

Quantum memory transfer time of ~10 ns

Fidelity of 97% in quantum state transfer

Enables many storage/retrieval cycles within flux qubit lifetimes

Abstract

We propose a long-lived and rapidly accessible quantum memory unit, for which the operational Hilbert space is spanned by states involving the two macroscopically occupied hyperfine levels of a miscible binary atomic Bose-Einstein condensate and the Rydberg state of a single atom. It is shown that an arbitrary qubit state, initially prepared using a flux qubit, can be rapidly transferred to and from the trapped atomic ensemble in approximately 10 ns and with a large fidelity of 97%, via an effective two-photon process using an external laser for the transition to the Rydberg level. The achievable ultrafast transfer of quantum information therefore enables a large number of storage and retrieval cycles from the highly controllable quantum optics setup of a dilute ultracold gas, even within the typically very short flux qubit lifetimes of the order of microseconds.