The reaction coordinate quantum master equation: Applications to nonequilibrium transport problems
Dvira Segal, University of Toronto
I will discuss the principles of the reaction coordinate (RC) quantum master equation (QME) method and its applications to quantum heat transport problems. The RC-QME technique allows considering, non-perturbatively, strong-coupling effects in quantum dynamics and transport. I will begin by describing the RC mapping, which has been used in the past to study quantum dissipative dynamics. Focusing on nonequilibrium heat transport problems, I will talk about our recent work with the RC-QME method:
(i) We simulated heat transport in the generalized non-equilibrium spin-boson model. Here, we studied the impact of strong system-bath couplings on sequential transport [1] as well as the emergence of high-order direct inter-bath heat current [2].
(ii) We studied the impact of strong coupling on the performance of quantum absorption refrigerators [3], a toy model for autonomous quantum thermal machines.
Beyond simulations, I will show that the RC mapping suggests the construction of effective model Hamiltonians that absorb strong coupling effects into renormalized parameters, allowing analytical work and economic simulations.
[1] N. Anto Sztrikacs and D. Segal, Strong coupling effects in quantum thermal transport with the reaction coordinate method, New J. Phys. 23, 063036 (2021).
[2] N. Anto-Sztrikacs, F. Ivander, and D. Segal, Quantum Thermal Transport Beyond Second Order with the Reaction Coordinate Mapping, arXiv:2203.06165.
[3] F. Ivander, Ni. Anto-Sztrikacs and D. Segal, Strong system-bath coupling reshapes characteristics of quantum thermal machines, Phys. Rev. E 105, 034112 (2022).