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arXiv · 2401.15991

Measurement of the Chern Number for Non-Hermitian Chern Insulators

Hongfang Liu·Ming Lu·Shengdu Chai·Zhi-Qiang Zhang·Hua Jiang
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Abstract

The identification of the topological invariant of a topological system is crucial in experiments. However, due to the inherent non-Hermitian features, such determination is notably challenging in non-Hermitian systems. Here, we propose that the magnetic effect can be utilized to measure the Chern number of the non-Hermitian Chern insulator. We find that the splitting of non-Hermitian bands under the magnetic field is Chern number dependent. Consequently, one can easily identify the Chern number by analyzing these splitting sub-bands. From the experimental perspective, the measurement of non-Hermitian bands is demonstrated in LC electric circuits. Furthermore, we find that the non-Hermiticity can drive open (closed) orbits of sub-bands in the Hermitian limit closed (open), which can also be identified by our proposal. These phenomena highlight the distinctive capabilities of non-Hermitian systems. Our results facilitate the detection of Chern numbers for non-Hermitian systems and may motivate further studies of their topological properties.

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Hongfang Liu, Ming Lu, Shengdu Chai, Zhi-Qiang Zhang, Hua Jiang. 2024-01-29. Measurement of the Chern Number for Non-Hermitian Chern Insulators. https://arxiv.org/abs/2401.15991

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