Condensed Matter Physics Seminar: Luca Magazzu

Abstract: The Nakajima-Zwanzig approach to open quantum systems is applied to
steady-state transport across generic multi-level junctions coupled to bosonic or fermionic reservoirs.  Approximate expressions are provided for the steady-state boson transport up to fourth order. These generalize to multi-level systems the known results for the low-temperature thermal
conductance in the spin-boson model. With this formalism we study the problem of heat transport in a qubit-resonator junction modeled by the quantum Rabi
model. Nontrivial transport features emerge as a result of the interplay between the qubit-oscillator detuning and coupling strength. For quasi-degenerate spectra, nonvanishing steady-state coherences cause a suppression of the thermal conductance.