Ballistic thermal rectification in asymmetric three-terminal mesoscopic dielectric systems

By coupling a temperature probe to the asymmetric three-terminal mesoscopic dielectric system, ballistic thermal rectification at low temperature is analytically studied based on the Landauer formulation of transport theory. It is seen that thermal rectification is a purely quantum effect and the quantum statistics of phonons in thermal reservoirs is necessary. Moreover, when the phonon re-emits into the system from the temperature probe, energy changing is necessary to realize thermal rectification. Another necessary condition is the different asymmetries for phonons with different frequencies, which is reflected by the dependence of the ratio tau(RC)(omega)/tau(RL)(omega) on omega, the phonon's frequency, where tau(RC)(omega) and tau(RL)(omega) are respectively the transmission coefficients from two asymmetric terminals to the temperature probe. The analytical results are confirmed by extensive numerical simulations.