Using comprehensive exact diagonalization calculations on $θ\approx 3.7 ^{\circ}$ twisted bilayer MoTe$_2$ ($t$MoTe$_2$), as well as idealized Landau level models also relevant for lower $θ$, we extract general principles for engineering fractional topological insulators (FTIs) in realistic situations. First, in a Landau level setup at $ν=1/3+1/3$, we investigate what features of the interaction destroy an FTI. For both pseudopotential interactions and realistic screened Coulomb interactions, we find that sufficient suppression of the short-range repulsion is needed for stabilizing an FTI. We then study $θ\approx 3.7 ^{\circ}$ $t$MoTe$_2$ with realistic band-mixing and anisotropic non-local dielectric screening. Our finite-size calculations only find an FTI phase at $ν=-4/3$ in the presence of a significant additional short-range attraction $g$ that acts to counter the Coulomb repulsion at short distances. We discuss how further finite-size drifts, dielectric engineering, Landau level character, and band-mixing effects may reduce the required value of $g$ closer towards the experimentally relevant conditions of $t$MoTe$_2$. Projective calculations into the $n=1$ Landau level, which resembles the second valence band of $θ\simeq 2.1^\circ$ $t$MoTe$_2$, do not yield FTIs for any $g$, suggesting that FTIs at low-angle $t$MoTe$_2$ for $ν=-8/3$ and $-10/3$ may be unlikely. While our study highlights the challenges, at least for the fillings considered, to obtaining an FTI with transport plateaus, even in large-angle $t$MoTe$_2$ where fractional Chern insulators are experimentally established, we also provide potential sample-engineering routes to improve the stability of FTI phases.
Pressure-Tunable Generalized Wigner Crystal and Fractional Chern Insulator in twisted MoTe$_2$
Beijing Institute of Technology(北京理工大学);Beijing Key Laboratory of Quantum Matter State Control and Ultra-Precision Measurement Technology(北京量子物质态调控与超精密测量技术重点实验室)
Fractional Chern insulators in alternating twisted multilayer MoTe$_{2}$
Huazhong University of Science and Technology(华中科技大学);Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology(华中科技大学武汉国家高能磁场中心);Hubei Fundamental Research Center for Physics(湖北省物理基础研究中心)
Moiré-modulated $Γ$ valley in twisted bilayer and twisted double-bilayer MoTe$_2$
Tsinghua University(清华大学);Beijing Tsinghua Institute for Frontier Interdisciplinary Innovation(北京清华交叉信息研究院);Shanghai Jiao Tong University(上海交通大学);National Institute for Materials Science(国立研究开发法人物质·材料研究机构);Synchrotron SOLEIL(SOLEIL同步辐射中心);Diamond Light Source Ltd(钻石光源有限公司);Institute for Advanced Study, Tsinghua University(清华大学高等研究中心);Frontier Science Center for Quantum Information(量子信息前沿科学中心)
Van Hove Singularity-Driven Topological Magnetism in Twisted MoTe2
University of Washington(华盛顿大学);Harvard University(哈佛大学);Massachusetts Institute of Technology(麻省理工学院);University of California - Santa Barbara(加利福尼亚大学圣巴巴拉分校);National Institute for Materials Science(国立材料研究所)
Intervalley Band Crossing and Transition of Fractional Chern Insulators in Floquet Twisted Bilayer MoTe$_2$
Zhejiang Institute of Modern Physics, Zhejiang University(浙江大学现代物理研究所);Zhejiang Key Laboratory of Micro-Nano Quantum Chips and Quantum Control, School of Physics, Zhejiang University(浙江大学物理学院微纳量子芯片与量子控制浙江省重点实验室)
Chiral superconductivity from spin polarized Chern band in twisted MoTe$_2$
University of Tennessee, Knoxville(田纳西大学诺克斯维尔分校);Tsinghua University(清华大学);Max Planck Institute for Chemical Physics of Solids(马克斯·普朗克固体化学物理研究所);Los Alamos National Laboratory(洛斯阿拉莫斯国家实验室);Shanghai Jiao Tong University(上海交通大学);Center for Integrated Nanotechnologies (CINT)(综合纳米技术中心);Min H. Kao Department of Electrical Engineering and Computer Science, University of Tennessee, Knoxville(田纳西大学诺克斯维尔分校闵H. Kao电气与计算机工程系)
Large scale theoretical investigation of the phase diagram of twisted bilayer MoTe$_2$ at fractional fillings: agreements and contradictions with current experiments
Donostia International Physics Center(多诺西亚国际物理中心);Department of Physics and Quantum Theory Project, University of Florida(佛罗里达大学物理系与量子理论项目);Department of Physics, Princeton University(普林斯顿大学物理系);Geballe Laboratory for Advanced Materials, Departments of Applied Physics, Stanford University(斯坦福大学应用物理系吉贝尔先进材料实验室);IKERBASQUE, Basque Foundation for Science(伊克尔巴斯克,巴斯克科学基金会);Center for Computational Quantum Physics, Flatiron Institute(平顿研究所计算量子物理中心);Laboratoire de Physique de l’Ecole normale supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris-Diderot, Sorbonne Paris Cité(巴黎高等师范学校物理实验室,ENS,PSL大学,法国国家科学研究中心,索邦大学,巴黎狄德罗大学,索邦巴黎城)
Non-monotonic band flattening near the magic angle of twisted bilayer MoTe$_2$
Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory(斯坦福材料能源科学研究所,SLAC国家加速器实验室);Department of Physics, University of Washington(华盛顿大学物理系);Department of Physics, Boston College(波士顿学院物理系);Department of Physics, Massachusetts Institute of Technology(麻省理工学院物理系);Department of Applied Physics, Stanford University(斯坦福大学应用物理系);Research Center for Materials Nanoarchitectonics, National Institute for Materials Science(物质材料研究机构材料纳米结构研究中心);Research Center for Electronic and Optical Materials, National Institute for Materials Science(物质材料研究机构电子光学材料研究中心);Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory(SLAC国家加速器实验室斯坦福同步辐射光源);Advanced Light Source, Lawrence Berkeley National Laboratory(劳伦斯伯克利国家实验室先进光源);Department of Materials Science and Engineering, Stanford University(斯坦福大学材料科学与工程系);Department of Materials Science and Engineering, University of Washington(华盛顿大学材料科学与工程系);Department of Physics, Stanford University(斯坦福大学物理系);Geballe Laboratory for Advanced Materials, Stanford University(斯坦福大学吉贝尔高级材料实验室)
Superconductivity Proximate to Non-Abelian Fractional Spin Hall Insulator in Twisted Bilayer MoTe$_2$
Pohang University of Science and Technology(浦项科技大学);Ulsan National Institute of Science and Technology(蔚山科学技术院);Daegu Gyeongbuk Institute of Science and Technology (DGIST)(大邱庆北科学技术院);Korea Advanced Institute of Science and Technology(韩国科学技术院);Institute for Basic Science(基础科学研究院)
Fractional Chern Insulator and Quantum Anomalous Hall Crystal in Twisted MoTe$_2$
Institute of Theoretical Physics, Chinese Academy of Sciences(中国科学院理论物理研究所);School of Physical Sciences, University of Chinese Academy of Sciences(中国科学院大学物理科学学院);National High Magnetic Field Lab(国家强磁场实验室)
Electric-field-tuned consecutive topological phase transitions between distinct correlated insulators in moire MoTe2/WSe2 heterobilayer
State Key Laboratory of Micro-nano Engineering Science, Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University(上海交通大学物理与天文学院,微纳工程科学国家重点实验室,人工结构与控制教育部重点实验室);School of Applied and Engineering Physics, Cornell University(康奈尔大学应用与工程物理学院);Departments of Physics and Applied Physics, Stanford University(斯坦福大学物理与应用物理系);National Institute for Materials Science(日本物质材料研究机构);SLAC National Accelerator Laboratory(斯坦福直线加速器国家实验室);Tsung-Dao Lee Institute, Shanghai Jiao Tong University(上海交通大学李政道研究所);Laboratory of Atomic and Solid State Physics, Cornell University(康奈尔大学原子与固态物理实验室);Kavli Institute at Cornell for Nanoscale Science(康奈尔大学卡弗里纳米科学研究所);Max Planck Institute for the Structure and Dynamics of Matter(德国马普物质结构与动力学研究所)
School of Physics and Astronomy, University of Minnesota(明尼苏达大学物理与天文学院);William I. Fine Theoretical Physics Institute, University of Minnesota(明尼苏达大学威廉·I·芬恩理论物理研究所)
Interplay between topology and electron-electron interactions in the moiré MoTe$_{\mathrm{2}}$/WSe$_{\mathrm{2}}$ heterobilayer
Academic Centre for Materials and Nanotechnology, AGH University of Krakow(AGH科技大学材料与纳米技术学术中心);Department of Quantum Matter Physics, University of Geneva(日内瓦大学量子物质物理系)
From fractional Chern insulators to topological electronic crystals in moiré MoTe2: quantum geometry tuning via remote layer
Shanghai Jiao Tong University(上海交通大学);Tsung-Dao Lee Institute, Shanghai Jiao Tong University(上海交大凌波研究院);Max Planck Institute for Chemical Physics of Solids(马克斯·普朗克固体化学物理研究所);National Institute for Materials Science(国立材料研究所);Hefei National Laboratory(合肥国家实验室);Shanghai Research Center for Quantum Sciences(上海量子科学研究中心);University of Tennessee(田纳西大学)
Characterization of fractional Chern insulator quasiparticles in twisted homobilayer MoTe$_2$
Zhejiang Institute of Modern Physics, Zhejiang University(浙江大学现代物理研究所);School of Physics, Zhejiang University(浙江大学物理学院);School of Physics and Technology, Wuhan University(武汉大学物理科学与技术学院);Wuhan Institute of Quantum Technology(武汉量子技术研究院)
Candidate for a Fractional Topological Insulator in Twisted MoTe2
Columbia University(哥伦比亚大学);University of Washington(华盛顿大学);University of Texas at Dallas(德克萨斯大学达拉斯分校);National Institute for Materials Science(国立材料研究所);Flatiron Institute(平顿研究所);Princeton University(普林斯顿大学);PSL University(巴黎文理研究大学)