We address both theoretically and experimentally the influence of asymmetric perturbation on the eigenvalues of parity-time (PT) symmetric resonator systems under the symmetric gain-loss arrangement, based on an inductively coupled inductor-capacitor-resistor (LCR) pair. The perturbed eigenvalues have been theoretically presented, numerically simulated, and experimentally measured. It shows that the asymmetric perturbation breaks PT-symmetry, leading to complex eigenvalues, which is different from the broken PT-symmetric phase with complex-conjugate eigenvalues. We have analyzed the perturbed frequency responses in all phases. At the exceptional points (EP), the resulting eigenvalues splitting is proportional to the square root of perturbation, showing the advantage of being highly sensitive to asymmetric perturbation. Meanwhile, the smaller the perturbation, the higher the sensitivity. The perturbation effect of PT-symmetric systems may be utilized to detect small signal changes in LC passive wireless sensors.

我们从理论上和实验上解决了不对称扰动对对称增益-损耗排列下奇偶时间 ( PT ) 对称谐振器系统特征值的影响，基于电感耦合电感-电容-电阻 ( LCR)对。扰动的特征值已在理论上提出、数值模拟和实验测量。表明非对称扰动破坏了PT对称性，导致复杂的特征值，这与破坏的PT不同- 具有复共轭特征值的对称相位。我们已经分析了所有相位的扰动频率响应。在异常点 (EP) 处，所得特征值分裂与扰动的平方根成正比，显示出对非对称扰动高度敏感的优势。同时，扰动越小，灵敏度越高。PT对称系统的扰动效应可用于检测LC无源无线传感器中的小信号变化。