Decay and renormalization of a longitudinal mode in a quasi-two-dimensional antiferromagnet.

ABSTRACT: An ongoing challenge in the study of quantum materials, is to reveal and explain collective quantum effects in spin systems where interactions between different modes types are important. Here we approach this problem through a combined experimental and theoretical study of interacting transverse and longitudinal modes in an easy-plane quantum magnet near a continuous quantum phase transition. Our inelastic neutron scattering measurements of Ba₂FeSi₂O₇ reveal the emergence, decay, and renormalization of a longitudinal mode throughout the Brillouin zone. The decay of the longitudinal mode is particularly pronounced at the zone center. To account for the many-body effects of the interacting low-energy modes in anisotropic magnets, we generalize the standard s

SUBMITTER: Do SH 

PROVIDER: S-EPMC8429660 | biostudies-literature | 2021 Sep

REPOSITORIES: biostudies-literature