Magnetic resonance spectroscopy and characterization of magnetic phases for spinor Bose-Einstein condensates

TL;DR

This paper develops a theoretical framework using linear response theory to analyze how spinor Bose-Einstein condensates respond to magnetic field modulations, enabling phase characterization through energy absorption spectra.

Contribution

It introduces a formalism linking energy absorption rate spectra to magnetic phase identification in spinor BECs, advancing experimental and theoretical understanding.

Findings

EAR spectrum distinguishes different magnetic phases

Quadratic spin correlations are accessible via response functions

Method applicable to spin-1 condensates

Abstract

The response of spinor Bose-Einstein condensates to dynamical modulation of magnetic fields is discussed with linear response theory. As an experimentally measurable quantity, the energy absorption rate (EAR) is considered, and the response function is found to access quadratic spin correlations which come from the perturbation of the quadratic Zeeman term. By applying our formalism to spin-1 condensates, we demonstrate that the EAR spectrum as a function of the modulation frequency is able to characterize the different magnetically ordered phases.