Quantum-interference-induced magnon blockade and antibunching in a hybrid quantum system

In this work, we study the phenomena of quantum-interference-assisted magnon blockade and magnon antibunching in a weakly interacting hybrid ferromagnet-superconductor system. The magnon excitations in two yttrium iron garnet spheres are indirectly coupled to a superconducting qubit through microwave cavity modes of two mutually perpendicular cavities. We find that when one of the magnon modes is driven by a weak microwave field, the destructive interference between more than two distinct transition pathways restricts the simultaneous excitation of two magnons. We analyze the magnon correlations in the driven magnon mode for the case of zero detunings as well as finite detunings of the magnon modes and the qubit. We show that the magnon antibunching can be tuned by changing the magnon-qubit coupling strength ratio and the driving detuning. Our work proposes a possible scheme that has a significant role in the construction of single magnon generating devices.