Résultats de recherche pour « Cavity Magnonics »

We present a scheme to generate the macroscopic Gaussian cluster states of multiple ferrimagnetic spheres in a microwave cavity through Kerr interactions. When each such sphere with self-Kerr nonlinearity is coupled to a single-cavity mode, it allows the generation of multimode entanglement and graph states—an important resource for one-way quantum computing through measurement-based protocols—near the strong and in the weak coupling regimes. While optimizing such states over the parameters governing the dynamics, the optimal appears for a far-detuned as well as dissipative cavity. Cluster states for a linear and a ring topology of a few spheres are discussed in the steady state of the system, further applicable to multiple spheres ( n = 10 ) , for experimentally feasible parameters.

Abstract The study of cavity magnonics and topological insulators has made significant advances over the past decade, however the possibility of combining the two fields is still unexplored. Here, we explore such connection by investigating hybrid cavity systems that incorporate both a ferromagnet and a topological insulator. We find that electrons in the topological surface state efficiently mediate the effective electric dipole coupling between the spin of the ferromagnet and the electric field of the cavity, in contrast with the conventional cavity magnonics theory based on magnetic dipole coupling. We refer to this coupling as topological magnon-photon interaction, estimating it one order of magnitude stronger than the conventional magnon-photon coupling, and showing that its sign can be manipulated. We discuss the potential of our proposed device to allow for scaling down and controlling the cavity system using electronics. Our results provide solid ground for exploring the functionalities enabled by merging cavity magnonics with topological insulators.

Magnetic domain walls (DWs) are topological defects that host robust low-energy modes, which can be harnessed for classical and neuromorphic computing. However, accessing their quantum dynamics has remained an outstanding challenge. Using concepts from cavity optomechanics, we show that a geometric, Coriolis-type interaction between localized DWs and extended magnon modes in short insulating ferromagnetic wires enables efficient cooling of DWs to their quantum ground state and the preparation of nonclassical states with negative Wigner functions, detectable in the power spectrum of emitted magnons. We further demonstrate that magnons can mediate long-range entangling interactions between qubits encoded in spatially separated DWs, providing a route toward universal quantum gate operations. Our proposal relies solely on intrinsic degrees of freedom of the ferromagnet and naturally extends to ferrimagnets and antiferromagnets, as well as to other confined magnetic textures such as vortices and skyrmions in insulating nanostructures.