Nuclear spin relaxation induced by a mechanical resonator

TL;DR

This study investigates how mechanical resonator-induced noise affects nuclear spin relaxation times in magnetic resonance force microscopy, revealing the dependence on magnetic field gradient, Rabi frequency, and temperature.

Contribution

It demonstrates the influence of magneto-mechanical noise on nuclear spin relaxation, providing a quantitative analysis linking mechanical thermal motion to spin lifetime.

Findings

Spin lifetime is governed by magneto-mechanical noise from thermal cantilever motion.

Relaxation rates depend on magnetic field gradient, Rabi frequency, and temperature.

Experimental results align with theoretical calculations based on spectral density of noise.

Abstract

We report on measurements of the spin lifetime of nuclear spins strongly coupled to a micromechanical cantilever as used in magnetic resonance force microscopy. We find that the rotating-frame correlation time of the statistical nuclear polarization is set by the magneto-mechanical noise originating from the thermal motion of the cantilever. Evidence is based on the effect of three parameters: (1) the magnetic field gradient (the coupling strength), (2) the Rabi frequency of the spins (the transition energy), and (3) the temperature of the low-frequency mechanical modes. Experimental results are compared to relaxation rates calculated from the spectral density of the magneto-mechanical noise.