Chiral current in Floquet cavity-magnonics

TL;DR

This paper demonstrates how Floquet engineering can induce chiral current transfer in cavity-magnonic systems, breaking time-reversal symmetry and enabling robust, phase-controlled interactions for quantum information processing.

Contribution

It introduces a novel Floquet-based method to generate chiral currents in cavity-magnonic systems, applicable to continuous-variable states and robust against systematic errors.

Findings

Realization of chiral state transfer via Floquet drive on magnon frequencies.

Effective Hamiltonian enabling phase-modulated, indirect magnon coupling.

Robustness of the protocol against coupling strength errors and Kerr nonlinearity.

Abstract

Floquet engineering can induce complex collective behaviour and interesting synthetic gauge-field in quantum systems through temporal modulation of system parameters by periodic drives. Using a Floquet drive on frequencies of the magnon modes, we realize a chiral state-transfer in a cavity-magnonic system. The time-reversal symmetry is broken in such a promising platform for coherent information processing. In particular, the photon mode is adiabatically eliminated in the large-detuning regime and the magnon modes under conditional longitudinal drives can be indirectly coupled to each other with a phase-modulated interaction. The effective Hamiltonian is then used to generate chiral currents in a circular loop, whose dynamics is evaluated to measure the symmetry of the system Hamiltonian. Beyond the dynamics limited in the manifold with a fixed number of excitations, our protocol applies to the continuous-variable systems with arbitrary states. Also it is found to be robust against the systematic errors in the photon-magnon coupling strength and Kerr nonlinearity.