Quantum transient heat transport in the hyper-parametric oscillator

TL;DR

This paper investigates quantum heat transport in nonlinear bosonic systems with hyper-parametric oscillation, revealing a cooling mechanism via ground state transitions and contrasting it with Kerr-type interactions.

Contribution

It introduces a novel analysis of hyper-parametric oscillation effects on quantum heat transport, demonstrating cooling phenomena not present in Kerr-type interactions.

Findings

System exhibits negative excitation mode.

Cooling occurs via ground state transition with increasing particles.

Cooling effect persists with two baths at different temperatures.

Abstract

We explore nonequilibrium quantum heat transport in nonlinear bosonic systems in the presence of a non-Kerr-type interaction governed by hyper-parametric oscillation due to two-photon hopping between the two cavities. We estimate the thermodynamic response analytically by constructing the $su(2)$ algebra of the nonlinear Hamiltonian and predict that the system exhibits a negative excitation mode. Consequently, this specific form of interaction enables the cooling of the system by inducing a ground state transition when the number of particles increases, even though the interaction strength is small. We demonstrate a transition of the heat current numerically in the presence of symmetric coupling between the system and bath and show long relaxation times in the cooling phase. We compare with the Kerr-type Bose-Hubbard form of interaction induced via cross-phase modulation, which does not exhibit any such transition. We further compute the nonequilibrium heat current in the presence of two baths at different temperatures and observe that the cooling effect for the non-Kerr-type interaction persists. Our findings may help in the manipulation of quantum states using the system's interactions to induce cooling.