Tomorrow's seminar

[CM ICTP - Trieste]

JOINT ICTP/SISSA STATISTICAL PHYSICS SEMINAR



Tuesday, 13 May    -    12:30 hrs.



Seminar Room - ICTP Leonardo Building-1st floor



F. ESSLER ( University of Oxford )



" Finite- temperature lineshapes in gapped quantum spin chains "


Abstract

We consider the finite-temperature dynamical suscepibility, X(T), of 
gapped quantum spin chains such as the integer spin Heisenberg model 
and the transverse field Ising model.  At zero temperature  X  in these 
models is dominated by a delta-function line arising from the coherent 
propagation of single particle modes.  Using methods of integrable 
quantum field theory we determine the evolution of the lineshape at low 
temperatures.  We show that the line shape is in general asymmetric in 
energy.  We discuss the application of our results to inelastic neutron 
scattering experiments on gapped spin chain systems such as YBaNiO_5.