Quantum heat transfer through an atomic wire

TL;DR

This paper investigates quantum phononic heat transfer in atomic wires, revealing stepwise thermal conductance behavior at low temperatures due to ballistic transport and resonance modes, using a model Hamiltonian approach.

Contribution

It introduces a model Hamiltonian approach to study quantum heat transfer in atomic wires, predicting stepwise conductance and resonance effects not previously detailed.

Findings

Thermal conductance is limited by a material-independent value at low temperatures.

Conductance exhibits stepwise behavior as a function of temperature.

Resonance modes in atomic chains influence thermal conductance.

Abstract

We studied the phononic heat transfer through an atomic dielectric wire with both infinite and finite lengths by using a model Hamiltonian approach. At low temperature under ballistic transport, the thermal conductance contributed by each phonon branch of a uniform and harmonic chain cannot exceed the well-known value which depends linearly on temperature but is material independent. We predict that this ballistic thermal conductance will exhibit stepwise behavior as a function of temperature. By performing numerical calculations on a more realistic system, where a small atomic chain is placed between two reservoirs, we also found resonance modes, which should also lead to the stepwise behavior in the thermal conductance.