Kinematic Modulation in Driven Spin Resonance

TL;DR

This paper reformulates the transition probability in driven spin resonance, revealing kinematic effects and providing a unified expression that improves upon classic models, especially under strong driving conditions.

Contribution

It introduces a new formulation accounting for measurement basis projection, highlighting kinematic modulation effects in spin resonance.

Findings

Identifies kinematic modulation in spin transition probabilities.

Derives a unified probability expression encompassing classic models.

Shows measurable deviations under strong driving conditions.

Abstract

The transition probability of a spin driven by a rotating magnetic field is reformulated. This work shows that, once projection onto the measurement basis is properly accounted for, the laboratory measured probability is governed by both intrinsic spin dynamics and the time dependence of the measurement basis. For the rotating-field eigenbasis, this yields an additional kinematic modulation, leading to measurable deviations under strong driving. A unified probability expression is derived that subsumes the classic 1937 and 1954 formulations as limiting cases, while correcting the conventional treatment of magnetic resonance transitions.