Relaxation Regimes of Spin Maser

TL;DR

This paper theoretically investigates various relaxation regimes in a spin maser, identifying seven distinct regimes and analyzing their initiation mechanisms, highlighting regimes beyond standard Bloch equation descriptions.

Contribution

It introduces a comprehensive classification of seven relaxation regimes in spin masers, including new regimes not captured by standard models.

Findings

Seven qualitatively different relaxation regimes identified.

Relaxation can be initiated by initial coherence or local spin fluctuations.

Nyquist noise does not affect macroscopic sample processes.

Abstract

Spin relaxation in a microscopic model of spin maser is studied theoretically. Seven qualitatively different regimes are found: free induction, collective induction, free relaxation, collective relaxation, weak superradiance, pure superradiance, and triggered superradiance. The initiation of relaxation can be originated either by an imposed initial coherence or by local spin fluctuations due to nonsecular dipole interactions. The Nyquist noise of resonator does not influence processes in macroscopic samples. The relaxation regimes not initiated by an imposed coherence cannot be described by the standard Bloch equations.