Multimode storage of quantum microwave fields in electron spins over 100 ms

TL;DR

This paper demonstrates a quantum memory using bismuth donor spins in silicon that can store microwave fields at the single-photon level for 100 milliseconds while preserving quantum coherence, advancing modular quantum computing.

Contribution

It introduces a long-lived, multi-mode quantum memory in silicon with 100 ms storage time using bismuth donors at a clock transition, suitable for quantum computing interfaces.

Findings

Stored microwave fields for 100 ms

Preserved phase coherence and quantum statistics

Achieved partial absorption and retrieval of quantum microwave fields

Abstract

A long-lived multi-mode qubit register is an enabling technology for modular quantum computing architectures. For interfacing with superconducting qubits, such a quantum memory should be able to store incoming quantum microwave fields at the single-photon level for long periods of time, and retrieve them on-demand. Here, we demonstrate the partial absorption of a train of weak microwave fields in an ensemble of bismuth donor spins in silicon, their storage for 100 ms, and their retrieval, using a Hahn-echo-like protocol. The long storage time is obtained by biasing the bismuth donors at a clock transition. Phase coherence and quantum statistics are preserved in the storage.