Long-lived driven solid-state quantum memory

TL;DR

This paper demonstrates that continuous dynamical decoupling can significantly enhance the storage time of inhomogeneously broadened spin ensemble quantum memories by suppressing noise and reshaping spectral inhomogeneity.

Contribution

It introduces the use of continuous driving fields to improve quantum memory performance by decoupling spins from noise and mitigating spectral inhomogeneity effects.

Findings

Continuous driving enhances spin coherence times.

Spectral inhomogeneity can be reshaped to improve memory.

Potential to increase storage time by orders of magnitude.

Abstract

We investigate the performance of inhomogeneously broadened spin ensembles as quantum memories under continuous dynamical decoupling. The role of the continuous driving field is two-fold: first, it decouples individual spins from magnetic noise; second and more important, it suppresses and reshapes the spectral inhomogeneity of spin ensembles. We show that a continuous driving field, which itself may also be inhomogeneous over the ensemble, can enhance the decay of the tails of the inhomogeneous broadening distribution considerably. This fact enables a spin ensemble based quantum memory to exploit the effect of cavity protection and achieve a much longer storage time. In particular, for a spin ensemble with a Lorentzian spectral distribution, our calculations demonstrate that continuous dynamical decoupling has the potential to improve its storage time by orders of magnitude for the state-of-art experimental parameters.