Nonequilibrium energy transport in driven-dissipative quantum systems

Abstract

Nonequilibrium energy transport serves as one of fundamental problems in quantum thermodynamics and quantum technologies. Driven quantum master equation in the dressed picture provides an efficient way of investigating nonequilibrium energy flow in general driven-dissipative quantum systems, where the systems are simultaneously driven by the finite thermodynamic bias and coherent driving field. The validity and general applicability of driven quantum master equation is confirmed by comparing with Floquet master equation, by analyzing energy currents in generic spin and boson models. The additional driving phase reserved in system-reservoir interactions, will apparently modify microscopic energy exchange processes. The steady-state energy currents are dramatically enhanced, in particular near the resonant regimes. In contrast, the traditional dressed master equation yields distinct behaviors of the energy currents. We hope that the driven quantum master equation may provide an efficient utility for the control of quantum transport and thermodynamic performances in driven-dissipative nanodevices.

Figures (6)

• Figure 1: (Color online) (a) Schematic of the driven-dissipative quantum system $\hat{H}_{\rm tot}$ at Eq. (\ref{['drivenH0']}), where the red and blue panels denote bosonic thermal reservoirs, the sphere embedded with multilevel structure describes the general quantum system, double arrowed curves describe system-reservoir couplings, and the brown spiral line with arrow means the external driving field onto the quantum system. (b) Two typical driving assisted up(down) incoherent transition processes from $|\phi_{n(m)}{\rangle}$ to $|\phi_{m(n)}{\rangle}$, characterized by the rates $\Gamma^\mu_{\pm}(\omega_d+E_{mn})$ at Eqs. (\ref{['R-']}) and (\ref{['R+']}).
• Figure 2: (Color online) Comparisons of energy currents into the $r$th thermal reservoir via the dDME, traditional DME, and FME in the nonequilibrium spin-boson model, by tuning (a) driving frequency $\omega_d$ with $\eta=0.1$ and (b) driving amplitude with $\omega_d=0.7$. Other system parameters are given by $\varepsilon=1$, $\alpha_l=\alpha_r=0.001$, $\omega_c=10$, $k_BT_l=1.2$, and $k_BT_r=0.4$.
• Figure 3: (Color online) Influences of the driving amplitude $\eta$ and frequency $\omega_d$ on steady-state energy currents into the (a) $r$th thermal reservoir, (b) $l$th reservoir, and (c) pump reservoir, via the dDME. (d) Behaviors of the energy currents by modulating $\omega_d$ with $\eta=0.1$. The pink regime denotes quantum transport is mainly dominated by two thermal reservoirs, with $J_p{\approx}0$; the blue regime means that the pumped flux $J_p$ surpasses $J_l$ to cooperatively contribute to $J_r$; the green regime demonstrates that $J_p$ is efficiently pumped into the thermal reservoirs against temperature bias. Other system parameters are given by $\varepsilon=1$, $\alpha_l=\alpha_r=0.001$, $\omega_c=10$, $k_BT_l=1.2$, and $k_BT_r=0.4$.
• Figure 4: (Color online) (a) Comparison of energy flows under dDME and FME in the nonequilibrium coupled-qubits model by modulating $\omega_d$, with $\eta=0.2$. (b) behaviors of energy flows by tuning $\eta$ with $\omega_d=0.9$. Other system parameters are given by $\varepsilon_l=\varepsilon_r=1$, $t=0.2$, $\alpha_l=\alpha_r=0.001$, $\omega_c=10$, $k_BT_l=1.2$, and $k_BT_r=0.4$.
• Figure 5: (Color online) Behaviors of the eat current $J_r$ in the nonequilibrium Kerr resonator model by tuning (a) the driving frequency $\omega_d$ with $\eta=0.1$ and (b) the driving amplitude $\eta$ with $\omega_d=0.5$. Other system parameters are given by $\varepsilon=1$, $\chi=0.4$, $\alpha_l=\alpha_r=0.001$, $\omega_c=10$, $k_BT_l=1.2$, and $k_BT_r=0.4$.