Entangling two magnon modes via magnetostrictive interaction

Abstract

We present a scheme to entangle two magnon modes in a cavity magnomechanical system. The two magnon modes are embodied by collective motions of a large number of spins in two macroscopic ferrimagnets, and couple to a single microwave cavity mode via magnetic dipole interaction. We show that by activating the nonlinear magnetostrictive interaction in one ferrimagnet, realized by driving the magnon mode with a strong red-detuned microwave field, the two magnon modes can be prepared in an entangled state. The entanglement is achieved by exploiting the nonlinear magnonphonon coupling and the linear magnon-cavity coupling, and is in the steady state and robust against temperature. The entangled magnon modes in two massive ferrimagnets represent genuinely macroscopic quantum states, and may find applications in the study of macroscopic quantum mechanics and quantum information processing based on magnonics.

Entangling the vibrational modes of two massive ferromagnetic spheres using cavity magnomechanics

“…In analogy to cavity optomechanics, in recent years cavity magnomechanics (CMM) [14] has received increasing attention, owing to its potential for realizing quantum states at a more macroscopic scale [15][16][17] and possible applications in quantum information processing and quantum sensing [18]. In these systems, a magnon mode (spin wave) of a ferromagnetic yttrium-iron-garnet (YIG) sphere couples to a microwave (MW) cavity field [19][20][21][22][23][24], and simultaneously couples to the vibrational phonon mode (deformation mode) of the sphere via the magnetostrictive force [25].…”

“…Quantum effects in CMM have been first studied in reference [15], which shows the possibility of creating genuine tripartite magnon-photon-phonon entanglement and cooling of the mechanical motion. Furthermore, proposals have been made for generating squeezed vacuum states of magnons and phonons [16], and entangled states of two magnon modes in CMM [17]. Quite recently, CMM has been used to produce stationary entangled MW fields by coupling a magnon mode to two MW cavities [33].…”

“…Quite recently, CMM has been used to produce stationary entangled MW fields by coupling a magnon mode to two MW cavities [33]. These protocols [15][16][17]33] essentially utilize the nonlinear magnetostrictive interaction effectively activated by properly driving the magnon mode with a magnetic field, which can be experimentally realized by directly driving the YIG sphere with a small MW loop antenna [34], allowing to implement the magnomechanical beamsplitter or two-mode squeezing interactions. Other quantum effects like tripartite Einstein-Podolsky-Rosen steering have also been studied [35].…”

Genuine photon-magnon-phonon Einstein-Podolsky-Rosen steerable nonlocality in a continuously-monitored cavity magnomechanical system

“…Cavity magnomechanical systems, in parallel with cavity optomechanical systems [13], represent a promising platform for studying macroscopic quantum phenomena [14,15], since the YIG sphere is around hundreds of micrometers in diameter, at the macroscopic scale. More interestingly, recent studies have already shown that quantum effects, such as quadrature squeezing, entanglement, and magnon quantum blockade, can be generated in cavity magnomechanics [16][17][18][19]. These findings inspire us to further explore novel quantum phenomena in the hybrid macroscopic quantum interface of photons, magnons, and phonons.…”

Phase-Controlled Pathway Interferences and Switchable Fast-Slow Light in a Cavity-Magnon Polariton System

“…We thus focus on the controllability of pathway interferences through the phase difference between the cavity-probe tone and the magnon-pump tone, which is introduced by the coupling loops' technology [61][62][63][64]. The direct magnon pump is becoming useful in realizing the light-wave interface [46][47][48], enhancing the Kerr nonlinearity [65][66][67], and has also been adopted to observe the magnetostrictioninduced quantum entanglement [68][69][70][71][72], among other applications.…”