Theory of spin relaxation in magnetic resonance force microscopy

TL;DR

This paper develops a theoretical model for spin relaxation in magnetic resonance force microscopy, explaining experimental results and proposing improvements to enhance sensitivity by reducing cantilever tip fluctuations.

Contribution

It introduces a theoretical framework for spin relaxation in MRFM under high-frequency mechanical noise and suggests engineering cantilevers to improve sensitivity.

Findings

Qualitative agreement with experimental relaxation times

Identification of high-frequency mechanical noise as a relaxation source

Proposal to reduce tip fluctuations for better sensitivity

Abstract

We study relaxation of a spin in magnetic resonance force microscopy (MRFM) experiments. We evaluate the relaxation rate for the spin caused by high-frequency mechanical noise of the cantilever under the conditions of adiabatic spin inversion. We find qualitative agreement between the obtained relaxation time and the experimental results of Stipe {\it et al.} [Phys. Rev. Lett. 87, 277602 (2001)]. Based on our analysis, we propose a method for improving the MRFM sensitivity by engineering cantilevers with reduced tip positional fluctuations.