Cavity cooling of an ensemble spin system

TL;DR

This paper explores applying sideband cooling techniques from quantum optics to large spin ensembles in magnetic resonance, enabling rapid polarization and entropy removal, which benefits quantum information processing.

Contribution

It introduces a theoretical framework for cavity cooling of large spin ensembles using the Tavis-Cummings model, demonstrating potential for significantly faster polarization than thermal relaxation.

Findings

Cooling rates scale favorably with ensemble size

Polarization of $10^{11}$ spins achievable in short times

Bridges quantum optics and magnetic resonance techniques

Abstract

We describe how sideband cooling techniques may be applied to large spin ensembles in magnetic resonance. Using the Tavis-Cummings model in the presence of a Rabi drive, we solve a Markovian master equation describing the joint spin-cavity dynamics to derive cooling rates as a function of ensemble size. Our calculations indicate that the coupled angular momentum subspaces of a spin ensemble containing roughly $10^{11}$ electron spins may be polarized in a time many orders of magnitude shorter than the typical thermal relaxation time. The described techniques should permit efficient removal of entropy for spin-based quantum information processors and fast polarization of spin samples. The proposed application of a standard technique in quantum optics to magnetic resonance also serves to reinforce the connection between the two fields, which has recently begun to be explored in further detail due to the development of hybrid designs for manufacturing noise-resilient quantum devices.