Scalable quantum memory in the ultrastrong coupling regime

TL;DR

This paper proposes a scalable quantum memory system in the ultrastrong coupling regime of circuit QED, demonstrating fast storage and retrieval of quantum information with potential for quantum random-access memory.

Contribution

It introduces a novel qubit-resonator system operating in the ultrastrong coupling regime for quantum memory applications, with feasible experimental schemes.

Findings

Effective quantum memory in the ultrastrong coupling regime

Fast quantum information storage and retrieval

Potential for scalable quantum random-access memory

Abstract

Circuit quantum electrodynamics, consisting of superconducting artificial atoms coupled to on-chip resonators, represents a prime candidate to implement the scalable quantum computing architecture because of the presence of good tunability and controllability. Furthermore, recent advances have pushed the technology towards the ultrastrong coupling regime of light-matter interaction, where the qubit-resonator coupling strength reaches a considerable fraction of the resonator frequency. Here, we propose a qubit-resonator system operating in that regime, as a quantum memory device and study the storage and retrieval of quantum information in and from the Z2 parity-protected quantum memory, within experimentally feasible schemes. We are also convinced that our proposal might pave a way to realize a scalable quantum random-access memory due to its fast storage and readout performances.