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arXiv · 2305.00900

Observation of higher-order exceptional points in pseudo-Hermitian radio-frequency circuits

Ke Yin·Xianglin Hao·Yuangen Huang·Jianlong Zou·Xikui Ma·Tianyu Dong
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Abstract

Exceptional points (EP) in non-Hermitian systems have been widely investigated due to their enhanced sensitivity in comparison to standard systems. In this letter, we report the observation of higher-order pseudo-Hermitian degeneracies in an electronic platform comprised of three inductively coupled gain-loss-loss LC resonators. Theoretical analysis demonstrates that the proposed system can realize third-order EP with asymmetric coupling between adjacent inductors and an arbitrary scaling factor between two loss resonators. When capacitive perturbation is introduced on the middle resonator, the perturbed eigenfrequencies follow a cube-root dependence on the perturbation parameter; in this case, the sensitivity is significantly greater than conventional wireless readout methods. Our work enriches the explorations of higher-order EP on electronic platforms and provides a new degree of design freedom for the non-Hermitian-EP-enhanced wireless sensing system.

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Ke Yin, Xianglin Hao, Yuangen Huang, Jianlong Zou, Xikui Ma, Tianyu Dong. 2023-04-18. Observation of higher-order exceptional points in pseudo-Hermitian radio-frequency circuits. https://arxiv.org/abs/2305.00900

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