Spin 1/2-3/2 crossover in a chain antiferromagnet
Phys. Rev. Materials 10, 104406 – Published 13 October, 2026
DOI: https://doi.org/10.1103/jbjp-kjwx
Abstract
We perform a 40–250 GHz electron spin resonance (ESR) study of the spin-chain quantum magnet in a paramagnetic phase. A continuous crossover from spin-3/2 to pseudospin-1/2 ESR was found when lowering the temperature from 15 to 3 K. This observation provides direct spectroscopic confirmation of a concept of pseudospins-1/2 used in the literature for a description of the low-temperature correlated state of this quantum magnet.
