Quantum heat transfer through an atomic wire

We studied the phononic heat transfer through an atomic dielectric wire wit h both infinite and finite lengths by using a model Hamiltonian approach. A t low temperature under ballistic transport, the thermal conductance contri buted by each phonon branch of a uniform and harmonic chain cannot exceed t he well known value which depends linearly on temperature but is material i ndependent. We predict that this ballistic thermal conductance will exhibit stepwise behaviour as a function of temperature. By performing numerical c alculations on more realistic systems, where small atomic chains are placed between two reservoirs, we also found resonant modes, which should also le ad to stepwise behaviour in the thermal conductance.