Journal of Physics Conference Series
Elementary excitations inS= 1/2 Heisenberg spin chains with alternatingg-tensor and the Dzyaloshinskii-Moriya interaction
Sergei A. Zvyagin, J. Wosnitza, Alexei K. Kolezhuk, J. Krzystek, R. Feyerherm
Abstract
The magnetic-excitation spectrum of copper pyrimidine dinitrate, a material containing S = 1/2 antiferromagnetic chains with alternating g -tensor and the Dzyaloshinskii-Moriya interaction, and exhibiting a field-induced spin gap, is probed using tunable-frequency electron spin resonance spectroscopy in magnetic fields up to 25 T. The data are interpreted in frame of the sine-Gordon quantum-field theoretical concept proposed recently by Oshikawa and Affleck. The field-induced gap is measured directly ; signatures of soliton and three breather branches are identified.