Optomechanical-interface-induced strong spin-magnon coupling

TL;DR

This paper proposes a hybrid optomechanical system that significantly enhances spin-magnon coupling via cavity squeezing, enabling efficient quantum state transfer for solid-state quantum information processing.

Contribution

It introduces a novel method to achieve strong, tunable spin-magnon coupling using optomechanical cavities and squeezing, advancing quantum interface technology.

Findings

Exponential amplification of coupling strengths through squeezing.

Generation of lower- and upper-branch polaritons (LBP and UBP).

Enhanced spin-magnon interaction via virtual LBP in the dispersive regime.

Abstract

Strong long-distance spin-magnon coupling is essential for solid-state quantum information processing and single qubit manipulation. Here, we propose an approach to realize strong spin-magnon coupling in a hybrid optomechanical cavity-spin-magnon system, where the optomechanical system, consisting of two cavities coupled to a common high-frequency mechanical resonator, acts as quantum interface. By eliminating the mechanical mode, a position-position coupling and two-mode squeezing of two cavities are induced. In the squeezing presentation, the spin-photon, magnon-photon and photon-photon coupling strengths are exponentially amplified, thus lower- and upper-branch polaritons (LBP and UBP) are generated by strongly coupled squeezed modes of two cavities. Utilizing the critical property of the LBP, the coupling between the spin qubit (magnon) and LBP is greatly enhanced, while the coupling between the spin qubit (magnon) and UBP is fully suppressed. In the dispersive regime, strong and tunable spin-magnon coupling is induced by the virtual LBP, allowing quantum state exchange between them. Our proposal provides a promising platform to construct magnon-based hybrid systems and realize solid-state quantum information processing with optomechanical interfaces.