Quantum Thermal Transport through Extremely Cold Dielectric Chains

In the framework of Green's function theory out of equilibrium, a Landauer--Buttiker (LB) formula for thermal conductance is derived. A simplified model for describing extremely cold dielectric chains is proposed for the first time. Further we apply the present LB formula for studying thermal conductance at low-lying modes, emerging in dielectric atom chains. We find that quantum thermal conductance undergoes an anomalous transition due to new quasiparticle excitations, resulting from nonlinear atom--atom interactions. This theoretical prediction is in excellent agreement with a high-accuracy measurement to thermal conductance quantum.