Probing low-energy excitations of ordered and critical antiferromagnets via Quantum Monte-Carlo

by Prof. Arnab Sen (IACS Kolkata)

Thursday, May 1, 2014 from 14:30 to 15:30 (Asia/Kolkata)
at Colaba Campus ( A304 )

Description

The low-energy spectrum of antiferromagnets reveal a lot about the
nature of the phase (or, phase transition) in such systems. We discuss
how to probe the dispersion of the excitations in a variety of SU(2)
symmetric S=1/2 spin systems using Quantum Monte-Carlo (QMC) methods.
Various applications of the method will be presented in one and two
dimensions, which include studying the critical excitations in 2D,
both for conventional and unconventional quantum critical points. In
the latter case, the excitation spectrum is highly unusual and has
additional gapless modes which are not present otherwise.