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arXiv · 2407.07894

Quantum-metric-induced quantum Hall conductance inversion and reentrant transition in fractional Chern insulators

Ang-Kun Wu·Siddhartha Sarkar·Xiaohan Wan·Kai Sun·Shi-Zeng Lin
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Abstract

The quantum metric of single-particle wave functions in topological flatbands plays a crucial role in determining the stability of fractional Chern insulating (FCI) states. Here, we unravel that the quantum metric causes the many-body Chern number of the FCI states to deviate sharply from the expected value associated with partial filling of the single-particle topological flatband. Furthermore, the variation of the quantum metric in momentum space induces band dispersion through interactions, affecting the stability of the FCI states. This causes a reentrant transition into the Fermi liquid from the FCI phase as the interaction strength increases.

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Ang-Kun Wu, Siddhartha Sarkar, Xiaohan Wan, Kai Sun, Shi-Zeng Lin. 2024-07-10. Quantum-metric-induced quantum Hall conductance inversion and reentrant transition in fractional Chern insulators. https://doi.org/10.1103/physrevresearch.6.l032063

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