Magnon Bundle in a Strongly Dissipative Magnet

Hybrid quantum systems based on magnetic platforms have witnessed the birth and fast development of quantum magnonics. Until now, most studies have relied on magnetic excitations in low-damping magnetic insulators, particularly yttrium iron garnet, while a large class of magnetic systems is ruled out in this interdisciplinary field. Here we propose the generation of a magnon bundle in a hybrid magnet-qubit system, where two or more magnons with the same energy and angular momentum are emitted simultaneously. By tuning the driving frequency of the qubit to match the detuning between magnon and qubit mode, one can effectively generate a magnon bundle via super-Rabi oscillations. In contrast with general wisdom, magnetic dissipation plays an enabling role in generating the magnon bundle, where the relaxation time of magnons determines the typical time delay between two successive magnons. The maximal damping that allows an antibunched magnon bundle can reach the order of 0.1, which may break the monopoly of low-dissipation magnetic insulators in quantum magnonics and enables a large class of magnetic materials for their applications in quantum manipulation. Further, our findings may provide a scalable and generic platform to study multimagnon physics and benefit the design of magnonic networks for quantum information processing.