Magnetic Signatures of a Putative Fractional Topological Insulator in Twisted MoTe2

Fuente: arXiv
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Autori principali: Wang, Yiping, Minarik, Gillian E., Li, Weijie, Kwan, Yves, Yuan, Shuai, Anderson, Eric, Hu, Chaowei, Ingham, Julian, Choe, Jeongheon, Taniguchi, Takashi, Watanabe, Kenji, Roy, Xavier, Chu, Jiun-Haw, Queiroz, Raquel, Hone, James C., Regnault, N., Xu, Xiaodong, Zhu, Xiaoyang
Natura: Preprint
Pubblicazione: 2026
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author Wang, Yiping
Minarik, Gillian E.
Li, Weijie
Kwan, Yves
Yuan, Shuai
Anderson, Eric
Hu, Chaowei
Ingham, Julian
Choe, Jeongheon
Taniguchi, Takashi
Watanabe, Kenji
Roy, Xavier
Chu, Jiun-Haw
Queiroz, Raquel
Hone, James C.
Regnault, N.
Xu, Xiaodong
Zhu, Xiaoyang
author_facet Wang, Yiping
Minarik, Gillian E.
Li, Weijie
Kwan, Yves
Yuan, Shuai
Anderson, Eric
Hu, Chaowei
Ingham, Julian
Choe, Jeongheon
Taniguchi, Takashi
Watanabe, Kenji
Roy, Xavier
Chu, Jiun-Haw
Queiroz, Raquel
Hone, James C.
Regnault, N.
Xu, Xiaodong
Zhu, Xiaoyang
contents The interplay among electronic correlation, topology, and time-reversal-symmetry (TRS) often leads to exotic quantum states of matter, as highlighted by the discoveries of fractional Chern insulators (FCIs) in twisted bilayer MoTe2 (tMoTe2). Among the FCIs in tMoTe2, the most robust is at a hole filling factor of v=-2/3 per moiré unit cell. Here, employing pump-probe circular dichroism (CD) measurement on tMoTe2 at twist angles (3.9 and 3.7 degrees), we show that a correlated state at v =-4/3 exhibits an unusual Ising antiferromagnet behavior. The v =-4/3 state with no net magnetization undergoes first order phase transitions at extremely low magnetic fields of ~ 2-6 mT to partially valley polarized (PVP) states. This behavior is notably absent for all other correlated states in tMoTe2 and also disappears for v =-4/3 at higher or lower twist angles (4.0 or 3.3 degree). The observed magnetic signature is consistent with a theoretically proposed fractional topological insulator (FTI), consisting of two copies of v =-2/3 FCIs with opposite chirality in the two K valleys. The experimental results are supported by interacting continuum model calculations that reveal the extreme closeness in energy ( < 1 meV) between the putative FTI and PVP states. Our findings present a candidate FTI with TRS and call for advanced transport and imaging measurements to establish the quantized helical edge modes.
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id arxiv_https___arxiv_org_abs_2601_18508
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Magnetic Signatures of a Putative Fractional Topological Insulator in Twisted MoTe2
Wang, Yiping
Minarik, Gillian E.
Li, Weijie
Kwan, Yves
Yuan, Shuai
Anderson, Eric
Hu, Chaowei
Ingham, Julian
Choe, Jeongheon
Taniguchi, Takashi
Watanabe, Kenji
Roy, Xavier
Chu, Jiun-Haw
Queiroz, Raquel
Hone, James C.
Regnault, N.
Xu, Xiaodong
Zhu, Xiaoyang
Strongly Correlated Electrons
The interplay among electronic correlation, topology, and time-reversal-symmetry (TRS) often leads to exotic quantum states of matter, as highlighted by the discoveries of fractional Chern insulators (FCIs) in twisted bilayer MoTe2 (tMoTe2). Among the FCIs in tMoTe2, the most robust is at a hole filling factor of v=-2/3 per moiré unit cell. Here, employing pump-probe circular dichroism (CD) measurement on tMoTe2 at twist angles (3.9 and 3.7 degrees), we show that a correlated state at v =-4/3 exhibits an unusual Ising antiferromagnet behavior. The v =-4/3 state with no net magnetization undergoes first order phase transitions at extremely low magnetic fields of ~ 2-6 mT to partially valley polarized (PVP) states. This behavior is notably absent for all other correlated states in tMoTe2 and also disappears for v =-4/3 at higher or lower twist angles (4.0 or 3.3 degree). The observed magnetic signature is consistent with a theoretically proposed fractional topological insulator (FTI), consisting of two copies of v =-2/3 FCIs with opposite chirality in the two K valleys. The experimental results are supported by interacting continuum model calculations that reveal the extreme closeness in energy ( < 1 meV) between the putative FTI and PVP states. Our findings present a candidate FTI with TRS and call for advanced transport and imaging measurements to establish the quantized helical edge modes.
title Magnetic Signatures of a Putative Fractional Topological Insulator in Twisted MoTe2
topic Strongly Correlated Electrons
url https://arxiv.org/abs/2601.18508