Origin of Pure Spin Superradiance

TL;DR

This paper investigates the origin of pure spin superradiance in polarized spin systems within resonators, revealing that local spin fluctuations, not resonator noise, trigger the phenomenon, emphasizing the importance of nonsecular dipole interactions.

Contribution

It provides a microscopic model and an accurate solution showing that local spin fluctuations, rather than resonator noise, initiate pure spin superradiance, highlighting the role of nonsecular dipole interactions.

Findings

Resonator Nyquist noise does not initiate superradiance.

Local spin fluctuations are the trigger for superradiance.

Nonsecular dipole interactions are crucial for the effect.

Abstract

The question addressed in this paper is: What originates pure spin superradiance in a polarized spin system placed inside a resonator? The term "pure" means that no initial coherence is imposed on spins, and its appearance manifests a purely self-organized collective effect. The consideration is based on a microscopic model with dipole spin interactions. An accurate solution of evolution equations is given. The results show that the resonator Nyquist noise does not play, contrary to the common belief, any role in starting spin superradiance, but the emergence of the latter is initiated by local spin fluctuations. The decisive role of nonsecular dipole interactions is stressed.