Control of heat transport in quantum spin systems
  We study heat transport in quantum spin systems analytically and numerically. First, we demonstrate that heat current through a two-level quantum spin system can be modulated from zero to a finite value by tuning a magnetic field. Second, we show that a spin system, consisting of two dissimilar parts - one is gapped and the other is gapless, exhibits current rectification and negative differential thermal resistance. Possible experimental realizations by using molecular junctions or magnetic materials are discussed. 
Yonghong Yan, Chang-Qin Wu, and Baowen Li