Nonlinear tripartite coupling of trapped electrons with magnons in a hybrid quantum system

Coherent nonlinear tripartite interactions are critical for quantum simulation and information processing in hybrid quantum systems, yet remain experimentally challenging and still evade comprehensive exploration. Here, we predict a nonlinear tripartite coupling mechanism in a hybrid setup comprising a single trapped electron and a nearby micromagnet. The tripartite coupling here leverages the electron’s motional and spin degrees of freedom interacting with the magnon modes of the micromagnet. Thanks to the large spatial extent of the electron zero-point motion, a tunable and strong spin-magnon-motion coupling can be obtained, with two phonons simultaneously interacting with a single spin and magnon excitation. This enables magnons to mediate coupling among distinct degrees of freedom of two electrons, allowing rapid preparation of few-body entangled states. This protocol is compatible with well-developed techniques in electron traps and quantum magnonics, and may open avenues for quantum simulations and hybrid quantum information processing by introducing a versatile platform for exploring multipartite interactions and nonclassical state generation. Coherent many-body interactions bring the quantum nature that is key to exploring quantum applications with multipartite entanglement. This work studies a nonlinear tripartite coupling mechanism in a hybrid quantum system, which provides an experimentally promising and reliable platform for manipulating few-body entangled quantum states.