Microscopic model of a phononic refrigerator

Abstract

We analyze a simple microscopic model to pump heat from a cold to a hot reservoir in a nanomechanical system. The model consists of a one-dimensional chain of masses and springs coupled to a back gate through which a time-dependent perturbation is applied. The action of the gate creates a moving phononic barrier by locally pinning a mass. We solve the problem numerically using a nonequilibrium Green function technique. For low driving frequencies and for sharp traveling barriers, we show that this microscopic model realizes a phonon refrigerator.

From Thermal Rectifiers to Thermoelectric Devices

“…In the steady state, currents and local densities can be obtained in terms of the so-called Keldysh Greens functions. This approach has been used, among other things, to study heat transport in driven nanoscale engines [6,8] and spin heterostructures [7]. Another commonly used approach to study heat transport in quantum systems is based on the GreenKubo formula, originally developed to study electric transport [80].…”

Dynamically induced heat rectification in quantum systems

“…To date, most theoretical proposals on classical heat rectifiers (see [1] and references therein) have been based either on the use of inohomogenous materials [2][3][4][5][6][7] exploiting nonlinear interactions, or doping the systems with impurities while remaining in the linear regime [8]. Also, the feasibility of microscopic systems acting as thermal devices has been recently addressed in, for instance, phononic refrigerators in the classical [9] and quantum [10] regimes, or heat rectifiers in diferent platforms: quantum dots [11], nonlinear solid-state quantum circuits [12], few-level systems [13,14], or hybrid configurations [15].…”

Dynamics of energy transport and entropy production in ac-driven quantum electron systems

“…Recently, linear response proposals in close relation to thermodynamics have been formulated for open quantum systems and quasiclassical systems under periodic driving [13,[31][32][33]. The proper definition of the heat exchange between a quantum driven system and its macroscopic environment has been recently addressed in the context of few-level or spin systems in contact to phononic baths [34][35][36] and in systems of coupled quantum harmonic oscillators [37][38][39].…”