AI 中文总结
该研究观测石墨烯-SiNx混合纳米机械系统的可调Fano共振，利用栅极控制Fano参数，实现石墨烯模式频率锁定，为高分辨率混合传感器等提供新平台。
AI 中文摘要
Fano共振源于离散态与连续态之间的干涉，在大量量子和经典系统中均有观测。本文实验观测了耦合振子模型的石墨烯-SiNx混合纳米机械系统中的Fano共振：宽低品质因子的石墨烯模式扮演连续态角色，而密集梳状的高品质因子SiNx模式提供离散态。模式间失谐可通过直流栅极电压调节，实现Fano共振的动态控制：我们展示了栅极控制下Fano不对称参数q的符号与大小的切换，与耦合振子理论定量吻合，该理论预测q=-cotφ，其中φ为连续态响应的相位。强驱动下，石墨烯模式进入杜芬（Duffing） regime，其跳变频率锁定于连续SiNx模式，产生驱动不敏感的频率平台阶梯；弱种子音可确定性地将谐振器在相邻锁定状态间切换。因此，密集SiNx模式在线性 regime中作为可调Fano干涉仪的离散态，在非线性 regime中作为稳定并量化石墨烯振荡的频率标尺。该平台提供了Fano干涉的可控机械实现，为高分辨率混合谐振传感器和稳定纳米机械频率基准开辟了新途径。
英文摘要
Fano resonances, arising from the interference between discrete and continuum states, are observed across a wide range of quantum and classical systems. Here, we report the experimental observation of Fano resonances in a graphene SiNx hybrid nanomechanical system modeled as coupled oscillators. The broad, low quality factor graphene mode plays the role of the continuum, while the dense comb of sharp, high quality factor SiNx modes provides the discrete states. The inter-mode detuning is tunable via a DC gate voltage, enabling dynamic control of the Fano resonance: we demonstrate gate controlled switching of both the sign and the magnitude of the Fano asymmetry parameter $q$, in quantitative agreement with a coupled oscillator theory that predicts $q=-\cotϕ$, with $ϕ$ the phase of the continuum response. At strong drive, the graphene mode enters the Duffing regime and its jump-down frequency locks to successive SiNx modes, producing a staircase of drive insensitive frequency plateaus; a weak seeding tone deterministically switches the resonator between adjacent locked states. The dense SiNx mode thus acts, in the linear regime, as the discrete states of a tunable Fano interferometer and, in the nonlinear regime, as a frequency ruler that stabilizes and quantizes the graphene oscillation. This platform offers a controllable mechanical realization of Fano interference and opens new avenues for high resolution hybrid resonant sensors and stable nanomechanical frequency references.
