Engineering quantum diode in one-dimensional time-varying superconducting circuits

A potential application, quantum diode based on the adiabatic pumping between two specific left and right edge modes, is explored in a one-dimensional cyclically modulated circuit quantum electrodynamic dimer mapped successfully to the paradigmatic Su-Schrieffer-Heeger model. The quantum diode is characterized by the presence of nonreciprocity in transport, which describes the one-way transfer between excitations at both boundary resonators of the lattice. We find that the quality of the quantum diode defined by fidelity can be improved by increasing the modulation amplitude, i.e., the one-way excitation transfer process becomes more and more pronounced with the increase of the modulation amplitude. By further modifying the cyclical modulation and optimizing the control function, we also realize a much faster one-way excitation transfer to accelerate the nonreciprocal transport in the quantum diode, where almost a threefold reduction in time spent can be achieved. Our work provides a distinct idea and insight for the application of the quantum transport in topological systems.