Resonances

Shachar Klaiman, Ido Gilary

Feiyu Wang, Jincheng Lu, Zi Wang +3 more

Nonequilibrium thermal transport in circuit quantum electrodynamics emerges as one interdisciplinary field, due to the tremendous advance of quantum technology. Here, we study steady-state heat flow in a two-mode qubit-resonator model under the influence of both the qubit-resonator and resonator-resonator interactions. The heat current is suppressed and enhanced by tuning up resonator-resonator interaction strength with given weak and strong qubit-resonator couplings respectively, which is cooperative contributed by the eigen-mode of coupled resonators and qubit-photon scattering. Negative differential thermal conductance and significant thermal rectification are exhibited at weak qubit-resonator coupling, which are dominated by cycle transition processes. Moreover, the heat flow through the resonator decoupled from the qubit can be dramatically enhanced via the resonator-resonator interaction, which is attributed by the generation of eigen-mode channels of resonators.

Norbert Dragon

Chee‐Kong Lee, L. C. Kwek, Jianshu Cao

We study the stochastic resonance of quantum discord (``discord resonance'') in coupled quantum systems and make a comparison with the stochastic resonance of entanglement (``entanglement resonance''). It is found that the discord resonance is much more robust against dephasing noise and thermal effects than the entanglement resonance. We also show that, unlike the entanglement resonance, the level of dissipation at which the discord resonance occurs is not sensitive to dephasing noise. These results suggest that it is easier to detect the discord resonance in actual experiments, where the dephasing noise and temperature are difficult to control.

Isabel Sainz, A. B. Klimov, S. M. Chumakov

The dynamics of a resonant atom interacting with a quantum cavity field in the presence of many off-resonant atoms is studied. In the framework of the effective Hamiltonian approach we show that the results of elimination of non-resonant transitions are (a) a dynamical Stark shift of the field frequency, dependent on the populations of non-resonant atoms, (b) dependence of the coupling constant between the resonant atom and the field on the populations of non-resonant atoms, and (c) an effective dipole–dipole interaction between non-resonant atoms. Two effects (the coherent influence and dephasing) of the off-resonant environment on the dynamics of the resonant atom are discussed.