Controlling the quantum dynamics of a mesoscopic spin bath in diamond

TL;DR

This paper demonstrates quantum control of a mesoscopic spin bath in diamond at room temperature, using an NV centre to probe and suppress decoherence, advancing quantum sensing and information processing.

Contribution

It introduces a method to control and measure the dynamics of a spin bath in diamond, enabling suppression of decoherence and new quantum applications.

Findings

Spin bath dynamics can be controlled at room temperature.

Spin bath control suppresses NV spin dephasing.

Direct measurement of bath spin correlations is achieved.

Abstract

Understanding and mitigating decoherence is a key challenge for quantum science and technology. The main source of decoherence for solid-state spin systems is the uncontrolled spin bath environment. Here, we demonstrate quantum control of a mesoscopic spin bath in diamond at room temperature that is composed of electron spins of substitutional nitrogen impurities. The resulting spin bath dynamics are probed using a single nitrogen-vacancy (NV) centre electron spin as a magnetic field sensor. We exploit the spin bath control to dynamically suppress dephasing of the NV spin by the spin bath. Furthermore, by combining spin bath control with dynamical decoupling, we directly measure the coherence and temporal correlations of different groups of bath spins. These results uncover a new arena for fundamental studies on decoherence and enable novel avenues for spin-based magnetometry and quantum information processing.