Laser Cooling of Nuclear Magnons

TL;DR

This paper proposes an optical method to efficiently cool nuclear magnons, collective nuclear spin excitations, significantly reducing their population and entropy, which advances their potential use in quantum information processing.

Contribution

It introduces an opto-nuclear quadrupolar effect enabling laser cooling of nuclear magnons, a novel approach for manipulating nuclear spins.

Findings

Nuclear magnons can be cooled by more than two orders of magnitude.

Optical interface enables efficient interaction with nuclear spins.

Potential applications in quantum information science.

Abstract

The initialization of nuclear spin to its ground state is challenging due to its small energy scale compared with thermal energy, even at cryogenic temperature. In this Letter, we propose an opto-nuclear quadrupolar effect, whereby two-color optical photons can efficiently interact with nuclear spins. Leveraging such an optical interface, we demonstrate that nuclear magnons, the collective excitations of nuclear spin ensemble, can be cooled down optically. Under feasible experimental conditions, laser cooling can suppress the population and entropy of nuclear magnons by more than two orders of magnitude, which could facilitate the application of nuclear spins in quantum information science.