Dynamical Spectra of Spin Supersolid States in Triangular Antiferromagnets

by Prof. Haijun Liao (Institute of Physics, Chinese Academy of Sciences)

Tuesday 20 Jan 2026, 11:00 → 12:00 Europe/Zurich

WBBC/111

Investigating dynamical excitations is crucial yet challenging, particularly for highly frustrated quantum antiferromagnets where conventional theories often fall short. In this talk, I will present our recent work using large-scale tensor network methods to investigate the spin excitations of spin supersolid states in triangular antiferromagnets under a magnetic field. Our calculations identify two distinct low-energy magnon excitations: a gapless Goldstone mode and a gapped mode. 

Focusing on their evolution with magnetic field, I will show how a characteristic roton excitation vanishes from the Goldstone mode within the Y-shaped superfluid phase, which we attribute to energy-level repulsion. Furthermore, I will discuss the contrasting absence of these roton excitations in the V-shaped supersolid phase, highlighting a key spectroscopic distinction between these two quantum states.