Magnon-exciton and magnon-photon couplings in CrSBr

Magnon-based hybrid quantum systems are promising candidates for quantum interconnects and quantum sensors, and they offer a rich platform for exploring nonlinear magnonics and cavity–photon interactions. Two-dimensional (2D) van der Waals magnets provide a compact, atomically flat geometry that can be easily integrated into existing quantum circuits, such as superconducting resonators and qubits. Among various 2D magnets, the magnetic semiconductor CrSBr is particularly unique due to its strong spin–exciton [1, 2], spin–lattice [3], and magnon–exciton [4] interactions. In this presentation, I will first discuss magnon-exciton coupling despite their energetical mismatch by orders of magnitude. I will then discuss our recent work demonstrating coherent coupling between antiferromagnetic magnons in CrSBr and microwave photons in a niobium-based-on-chip resonator [5]. This work demonstrates the first step toward integrating layered van der Waals 2D magnets into superconducting microwave circuits, with full access for both microwave and optical probing. Finally, I will discuss how these properties of magnetic semiconductors can be harnessed for spintronic devices and quantum information science.