Non‐Hermitian Broadside Coupled Split Ring Resonators with Directional Sensitivity (Advanced Optical Materials 17/2024)

Broadside-Coupled Split Ring Resonators This cover image features non-Hermitian broadside-coupled split ring resonators (BC-SRRs) that can identify the direction of a radio-frequency (RF) source (the luminous body at the center of a spherical wave). When an RF signal is incident upon the BC-SRRs at a specific angle, the resulting resonance responses of the two BC-SRRs exhibit varying strengths due to non-Hermitian coupling. This angular dependence of resonance strength difference, observed as the incident angle ranges from 0° to 180°, holds immense promise for applications such as microrobot positioning, automatic navigation, and robotic arm control. For further insights into this research, see article number 2302420 by Zhenci Sun, Xiaoguang Zhao, and co-workers.