Photo-induced superconducting diode effect via chiral cavity modes

Time reversal symmetry breaking is an important facet of controlling nonreciprocal responses. Here, we propose a method of photo-control over superconducting diode-like nonreciprocities, where time reversal symmetry breaking is achieved via photon exchange with chiral cavity modes. We reveal the origin of the nonreciprocal superconducting response as the embedding of chirality in a many-body ground state through photon induced orbital magnetization. With twisted bilayer graphene (TBG) as an example, we demonstrate the general principles of photo-control of diode responses, which are valid for a wide range of superconductors and cavity designs. The cavity control of superconducting nonreciprocities, particularly in the microwave regime, offers a non-invasive means of exploring new functionalities in quantum circuits with ultrafast switching and on-chip integration. This control method can serve as an important contribution to the toolbox for nonreciprocal models in circuit quantum electrodynamics, primed to be harnessed for scalable and modular quantum devices.