Simultaneous blockade of two remote magnons induced by an atom

In this paper, we present a scheme to simultaneously blockade two remote magnons by coupling them to an odd-number cavity array. In the system, a two-level atom is contained in the middle cavity and two Yttrium iron garnet (YIG) spheres are placed in the symmetrical cavity to the atom. By eliminating the cavity array, a master equation with the effective coherent and dissipative couplings among the two magnons and the atom is obtained. When the frequency of the atom is outside the cavity photon band, the dissipative couplings disappear, and only coherent couplings survive, but the effective dispersive coupling strength decreases rapidly with the increasing of the distance between two YIG spheres. When the frequency of the atom is inside band, although the induced dissipation cannot be eliminated, the dissipative coupling and the coherent coupling between two YIG spheres can coexist for long distance. We further show that, under the condition of single excitation resonance, the simultaneous blockade of two remote magnons can be obtained, but the thermal noise of the magnon and atom is still required to be depressed. Thus, by coupling a local two-level atom to a cavity array, we can simultaneously blockade two remote magnons, which provides us an effective method to manipulate remote YIG spheres.