arXiv:0704.2252
Negative differential conductivity in Heisenberg XXZ chain far from equilibrium
Tomaž Prosen
Abstract
Negative differential conductivity is reported for the far from equilibrium quantum spin transport in the insulating regime (J_x < J_z) of finite Heisenberg XXZ spin 1/2 chains. The phenomenon is reproduced analytically for small chains of N=4 spins and further analyzed numerically, for up to N=16, using an efficient pure-state simulation with stochastic spin baths.