Zhao Wenzheng, Zhang Yeang, Gao Zixuan, Peng Delong, Kou Jun-Long, Lu Yan-Qing, El-Ganainy Ramy, Özdemir Şahin K, Zhong Qi
School of Electronic Science and Engineering, Nanjing University, Nanjing, China.
School of Integrated Circuits, Nanjing University, Suzhou, China.
Nat Commun. 2024 Nov 15;15(1):9907. doi: 10.1038/s41467-024-53929-4.
Exceptional points in non-Hermitian systems have attracted considerable attention due to their novel applications in several fields such as optics, electronics, and mechanics. Typically, exceptional points are constructed through gain and loss modulation or dissipative coupling within the framework of parity-time symmetry or anti-parity-time symmetry. Recent demonstration of unidirectional coupling in optical resonators to create exceptional points has offered an alternative approach. This study extends this concept to electronic circuits, examining exceptional points that emerge in unidirectionally coupled LC circuits. We show that this circuit undergoes resonance frequency splitting that exhibits either linear or square-root scaling with the strength of the applied perturbation. We further explore the circuit's scattering properties when connected to an input-output channel and demonstrate both theoretically and experimentally the splitting of transmission dips or peaks when a perturbation is applied-highlighting the potential for building sensors with enhanced sensitivity. This work not only deepens the understanding of exceptional points in electronic circuits but also encourages the exploration and application of non-Hermiticity in electronics.
非厄米系统中的例外点因其在光学、电子学和力学等多个领域的新颖应用而备受关注。通常，例外点是通过在宇称-时间对称或反宇称-时间对称框架内的增益和损耗调制或耗散耦合来构建的。最近在光学谐振器中通过单向耦合创建例外点的演示提供了一种替代方法。本研究将这一概念扩展到电子电路，研究单向耦合LC电路中出现的例外点。我们表明，该电路会经历共振频率分裂，其与施加扰动的强度呈线性或平方根比例关系。我们进一步探讨了该电路连接到输入-输出通道时的散射特性，并在理论和实验上证明了施加扰动时传输凹陷或峰值的分裂——突出了构建具有更高灵敏度传感器的潜力。这项工作不仅加深了对电子电路中例外点的理解，也鼓励了在电子学中对非厄米性的探索和应用。
