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

by Prof. Arnab Sen (IACS Kolkata)

Thursday 1 May 2014, 14:30 → 15:30 Asia/Kolkata

A304 (Colaba Campus)

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.