Speaker: Liang Luo
Beijing Computational Science Research Center
Abstract: Gauge glass model is an extreme case of the randomly frustrated X-Y model, which is originally proposed in the study of disordered Josephson junction array (JJA) in a magnetic field. The spin vortex is the most important collective excitation in 2D gauge glass.In previous simulation studies, zero resistivity of the Josephson junction array was predicted for vanishing currents in low temperature regime, which suggested a vortex-glass transition at Tg~0.22. This conflicted with the theoretical prediction of the absence of a finite temperature phase transition in this 2D system. To resolve the disputes, we performed extensive resistive shunt junction (RSJ) simulation to lower currents, which suggests finite resistivity also for T<0.22. To understand the dynamics of 2D gauge glass, the transport properties of vortex on lattice are studied under nearly isolated approximation. Agreeing with RSJ simulation, the Arrhenius dependence of the mobility of the vortex is suggested by kinetic Monte Carlo simulation. Furthermore, the investigation of the linear and non-linear response in this almost localized system would provide another examination of the fluctuation-dissipation theorem.
Date&Time: May 18, 2012 14:30 - 15:00
Location: 606 Conference Room
