Elementary excitations of S=1/2 one-dimensional antiferromagnet KCuGaF6 in magnetic field and quantum sine-Gordon model

Izumi Umegaki, Toshio Ono, Hidekazu Tanaka +2

Elementary excitations of the S=1/2 one-dimensional Heisenberg antiferromagnet KCuGaF${}_6$ with exchange constant $J/k_B$=103 K were investigated by high-frequency ESR measurements…