Fourier's Law in a Quantum Spin Chain and the Onset of Quantum Chaos
  We study heat transport in a nonequilibrium steady state of a quantum interacting spin chain. We provide clear numerical evidence of the validity of Fourier law. The regime of normal conductivity is shown to set in at the transition to quantum chaos. 
Carlos Mejia-Monasterio, Tomaz Prosen, Giulio Casati