Abstract
We study the enhanced sensing of weak anharmonicities in a gain-based cavity-magnon-waveguide coupled system.By dissipatively coupling the two subsystems through a mediating waveguide,the Hamiltonian of the system is tailored to be anti-parity-time symmetric.Unique to the gain condition,the eigenvalues exhibit two singularities with linewidth suppression,distinguishing them from those of gain-free systems.Under the gain condition,a counter-intuitive bistable signature emerges even at low drive powers.As the effective gain approaches a certain value,this bistability yields a signif-icantly enhanced spin-current response of the magnon mode.Consequently,the sensitivity,quantified by an enhancement factor,is enhanced remarkably compared to the linewidth suppression scenario.Moreover,the high enhancement factor can be sustained over a broad gain-bandwidth and also stays large even when the coherent coupling becomes considerably strong.Based on the integrated cavity-magnon-waveguide systems,this scheme can be used for sensing different physical quantities related to the Kerr-type nonlinearity and has potential applications in high-precision measuring microwave-signal nonlinearities.
维普
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