Quantum phase transitions and unconventional behaviour in 2D quantum Heisenberg models

by Dr Sandro Wenzel (Univ. of Leipzig)

Wednesday 19 Nov 2008, 11:15 → 12:15 Europe/Zurich

EPFL, Salle 727 du BSP

I will talk about quantum phase transitions and critical exponents in a special class of 2D quantum Heisenberg antiferromagnets. In particular, I discuss recent quantum Monte Carlo results on the "staggered" Heisenberg model, which has been discussed in relation to the exciting notion of "deconfined quantum criticality". By a detailed comparison to other dimerized models, we show, contrary to the current belief, that the critical exponents of the staggered model are most likely not in agreement with the 3D classical Heisenberg universality class. I will also prenset further thermodynamic studies on the quantum criticial region which reinforce these findings.