Investigating the possibility of quantum thermal heat pumps in atom-scale devices

Electrons occupying 1D chains of atoms can have plasmonic excited states that arise due to the electron-electron interaction. These modes can be excited by dipolar coupling with a resonant quantum emitter at an end of the chain. We consider a system of a quantum emitter on one end of the chain resonant with the excitation of multiple plasmon modes of the chain and a quantum emitter on other end resonant with a singly excited lowest plasmon mode. If initially the higher energy emitter is excited and the chain and other emitter are in their ground states, unitary evolution shows the flow of energy from the high energy emitter, through the chain and into the far emitter, with some energy remaining in the chain and eventually flowing back into the first emitter. By coupling each emitter to a thermal bath at a different temperature, we may potentially have either a heat pump or heat engine that is driven by or drives an oscillating electromagnetic field due to the plasmon excitations. We investigate this possibility by simulating the open quantum system with stochastic evolution. We use an extended Fermi model of interacting many-body electrons, which are dipole coupled to two-level systems representing the emitters, which are then subject to stochastic jumps due to the thermal baths.