From fractional Chern insulators to topological electronic crystals in moiré MoTe2: quantum geometry tuning via remote layer

Fuente: arXiv
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Main Authors: Liu, Feng, Xu, Fan, Xu, Cheng, Li, Jiayi, Sun, Zheng, Xiao, Jiayong, Mao, Ning, Chang, Xumin, Tao, Xinglin, Watanabe, Kenji, Taniguchi, Takashi, Jia, Jinfeng, Zhong, Ruidan, Shi, Zhiwen, Wang, Shiyong, Chen, Guorui, Liu, Xiaoxue, Qian, Dong, Zhang, Yang, Li, Tingxin, Jiang, Shengwei
Format: Preprint
Published: 2025
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author Liu, Feng
Xu, Fan
Xu, Cheng
Li, Jiayi
Sun, Zheng
Xiao, Jiayong
Mao, Ning
Chang, Xumin
Tao, Xinglin
Watanabe, Kenji
Taniguchi, Takashi
Jia, Jinfeng
Zhong, Ruidan
Shi, Zhiwen
Wang, Shiyong
Chen, Guorui
Liu, Xiaoxue
Qian, Dong
Zhang, Yang
Li, Tingxin
Jiang, Shengwei
author_facet Liu, Feng
Xu, Fan
Xu, Cheng
Li, Jiayi
Sun, Zheng
Xiao, Jiayong
Mao, Ning
Chang, Xumin
Tao, Xinglin
Watanabe, Kenji
Taniguchi, Takashi
Jia, Jinfeng
Zhong, Ruidan
Shi, Zhiwen
Wang, Shiyong
Chen, Guorui
Liu, Xiaoxue
Qian, Dong
Zhang, Yang
Li, Tingxin
Jiang, Shengwei
contents The quantum geometry of Bloch wavefunctions,encoded in the Berry curvature and quantum metric, is believed to be a decisive ingredient in stabilizing fractional quantum anomalous Hall (FQAH) effect(i.e., fractional Chern insulator, FCI, at zero magnetic field), against competing symmetry-breaking phases.A direct experimental demonstration of quantum geometry-driven switching between distinct correlated topological phases, however, has been lacking. Here, we report experimental evidence of such a switch in a high-quality 3.7 twisted MoTe2 (tMoTe2) device consisting of both A-A bilayer and A-AB trilayer regions. While composite Fermi liquid CFL/FQAH phases are established in A-A tMoTe2,the A-AB region-effectively an A-A moire bilayer proximitized by a remote B layer-develops a series of topological electronic crystal (TEC, also referred to as generalized QAH crystal, QAHC) states with integer quantized Hall conductance at commensurate fractional fillings v=1/2, 2/3, and an incommensurate filling factor v=0.53.The electrostatic phase diagram is mapped out by combined transport and optical measurements, showing that these TEC states emerge within the first moir'e valence band prior to any charge transfer to the B layer. Exact diagonalization (ED) incorporating the remote-layer-induced intralayer potential demonstrates a transition from a CFL-like manifold in the A-A limit to a Chern number C=1 ground-state consistent with a TEC at v=1/2 , accompanied by the further breakdown of ideal band geometry. Our results provide experimental evidence of quantum geometry-tuned competition between FQAH/CFL and TEC phases in a moiré Chern band and pave the way for further exploring correlation-driven topological phenomena by tuning quantum geometry.
format Preprint
id arxiv_https___arxiv_org_abs_2512_03622
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle From fractional Chern insulators to topological electronic crystals in moiré MoTe2: quantum geometry tuning via remote layer
Liu, Feng
Xu, Fan
Xu, Cheng
Li, Jiayi
Sun, Zheng
Xiao, Jiayong
Mao, Ning
Chang, Xumin
Tao, Xinglin
Watanabe, Kenji
Taniguchi, Takashi
Jia, Jinfeng
Zhong, Ruidan
Shi, Zhiwen
Wang, Shiyong
Chen, Guorui
Liu, Xiaoxue
Qian, Dong
Zhang, Yang
Li, Tingxin
Jiang, Shengwei
Mesoscale and Nanoscale Physics
Strongly Correlated Electrons
The quantum geometry of Bloch wavefunctions,encoded in the Berry curvature and quantum metric, is believed to be a decisive ingredient in stabilizing fractional quantum anomalous Hall (FQAH) effect(i.e., fractional Chern insulator, FCI, at zero magnetic field), against competing symmetry-breaking phases.A direct experimental demonstration of quantum geometry-driven switching between distinct correlated topological phases, however, has been lacking. Here, we report experimental evidence of such a switch in a high-quality 3.7 twisted MoTe2 (tMoTe2) device consisting of both A-A bilayer and A-AB trilayer regions. While composite Fermi liquid CFL/FQAH phases are established in A-A tMoTe2,the A-AB region-effectively an A-A moire bilayer proximitized by a remote B layer-develops a series of topological electronic crystal (TEC, also referred to as generalized QAH crystal, QAHC) states with integer quantized Hall conductance at commensurate fractional fillings v=1/2, 2/3, and an incommensurate filling factor v=0.53.The electrostatic phase diagram is mapped out by combined transport and optical measurements, showing that these TEC states emerge within the first moir'e valence band prior to any charge transfer to the B layer. Exact diagonalization (ED) incorporating the remote-layer-induced intralayer potential demonstrates a transition from a CFL-like manifold in the A-A limit to a Chern number C=1 ground-state consistent with a TEC at v=1/2 , accompanied by the further breakdown of ideal band geometry. Our results provide experimental evidence of quantum geometry-tuned competition between FQAH/CFL and TEC phases in a moiré Chern band and pave the way for further exploring correlation-driven topological phenomena by tuning quantum geometry.
title From fractional Chern insulators to topological electronic crystals in moiré MoTe2: quantum geometry tuning via remote layer
topic Mesoscale and Nanoscale Physics
Strongly Correlated Electrons
url https://arxiv.org/abs/2512.03622