Higgs-like pair amplitude dynamics in superconductor-quantum-dot hybrids

We consider a quantum dot weakly tunnel coupled to superconducting reservoirs. A finite superconducting pair amplitude can be induced on the dot via the proximity effect. We investigate the dynamics of the induced pair amplitude after a quench and under periodic driving of the system by means of a real-time diagrammatic approach. We find that the quench dynamics is dominated by an exponential decay towards equilibrium. In contrast, the periodically driven system can sustain coherent oscillations of both the amplitude and the phase of the induced pair amplitude in analogy to Higgs and Nambu-Goldstone modes in driven bulk superconductors.

Automated summary

In this study, we investigated the dynamics of induced pair amplitude on a quantum dot weakly tunnel coupled to superconducting reservoirs. We found that after a quench, the system exhibits exponential decay towards equilibrium, while under periodic driving, coherent oscillations of both the amplitude and phase of the induced pair amplitude can be sustained, reminiscent of Higgs and Nambu-Goldstone modes in driven bulk superconductors.