Room-Temperature Quantum Bit Memory Exceeding One Second

TLDR

Stable, scalable quantum bits that can store information for macroscopic times are essential for many applications and offer robustness and versatility for future quantum technologies. The memory is a single 13C nuclear spin adjacent to a nitrogen‑vacancy center in isotopically purified diamond, whose coherence is extended by dissipative decoupling from its local environment. High‑fidelity control of the qubit preserves its polarization for minutes and yields coherence times over one second at room temperature.

Abstract

Stable quantum bits, capable both of storing quantum information for macroscopic time scales and of integration inside small portable devices, are an essential building block for an array of potential applications. We demonstrate high-fidelity control of a solid-state qubit, which preserves its polarization for several minutes and features coherence lifetimes exceeding 1 second at room temperature. The qubit consists of a single (13)C nuclear spin in the vicinity of a nitrogen-vacancy color center within an isotopically purified diamond crystal. The long qubit memory time was achieved via a technique involving dissipative decoupling of the single nuclear spin from its local environment. The versatility, robustness, and potential scalability of this system may allow for new applications in quantum information science.