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Related papers: Unconventional Fractional Phases in Multi-Band Vor…

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Recent experiments on the twisted semiconductor bilayer system $t$MoTe$_2$ have observed integer and fractional quantum anomalous Hall effects, which occur in topological moir\'e bands at zero magnetic field. Here, we present a global phase…

Mesoscale and Nanoscale Physics · Physics 2023-12-25 Aidan P. Reddy , Liang Fu

Collective modes of exotic quantum fluids reveal underlying physical mechanisms responsible for emergent complex quantum ground states. We observe unexpected new collective modes in the fractional quantum Hall (FQH) regime:…

Mesoscale and Nanoscale Physics · Physics 2019-11-05 Lingjie Du , Ursula Wurstbauer , Ken W. West , Loren N. Pfeiffer , Saeed Fallahi , Geoff C. Gardner , Michael J. Manfra , Aron Pinczuk

We present a detailed microscopic investigation of fractional quantum Hall states with gapped boundaries in a coupled bilayer lattice model featuring holes whose counterpropagating chiral edge states are hybridized and gapped out. We focus…

Strongly Correlated Electrons · Physics 2019-05-14 Zhao Liu , Emil J. Bergholtz

We present a pedagogical review of the physics of fractional Chern insulators with a particular focus on the connection to the fractional quantum Hall effect. While the latter conventionally arises in semiconductor heterostructures at low…

Strongly Correlated Electrons · Physics 2015-10-05 S. A. Parameswaran , R. Roy , S. L. Sondhi

Fractional quantum anomalous Hall effects realized in twisted bilayer MoTe$_2$ and multilayer-graphene-based moir\'e heterostructures have captured a tremendous growth of interest. In this work, we propose that rhombohedral multilayer…

Mesoscale and Nanoscale Physics · Physics 2025-03-17 Yanran Shi , Bo Xie , Fengfan Ren , Xinyu Cai , Zhongqing Guo , Qiao Li , Xin Lu , Nicolas Regnault , Zhongkai Liu , Jianpeng Liu

Two-dimensional moir\'e Chern bands provide an exceptional platform for exploring a variety of many-body quantum phases at zero magnetic field within a lattice system. One particular intriguing possibility is that flat Chern bands can, in…

Enhancing the many-body gap of a fractional state is crucial for realizing robust fractional excitations. For fractional Chern insulators, existing studies suggest that making flat Chern bands closely resemble the lowest Landau level (LLL)…

Strongly Correlated Electrons · Physics 2025-11-25 Yitong Zhang , Siddhartha Sarkar , Xiaohan Wan , Daniel E. Parker , Shi-Zeng Lin , Kai Sun

In the search of fractional quantum anomalous Hall (FQAH) effect, the conventional wisdom is to start from a flat Chern band isolated from the rest of the Hilbert space by band gaps, so that many-body interaction can be projected to a…

Mesoscale and Nanoscale Physics · Physics 2025-05-13 Wenqi Yang , Dawei Zhai , Tixuan Tan , Feng-Ren Fan , Zuzhang Lin , Wang Yao

We consider a topologically non-trivial flat band structure in one spatial dimension in the presence of nearest and next nearest neighbor Hubbard interaction. The non-interacting band structure is characterized by a symmetry protected…

Strongly Correlated Electrons · Physics 2013-07-30 Jan Carl Budich , Eddy Ardonne

Landau levels in certain models are known to protrude into the zero-field energy gap. These are known as anomalous Landau levels (ALLs). We study whether ALLs can lead to Fermi-surface like quantum oscillation in the absence of a zero-field…

Strongly Correlated Electrons · Physics 2026-04-28 Jianlong Fu , Chun Yu Weng , Hoi Chun Po

Since the discovery of the Fractional Quantum Hall Effect in 1982 there has been considerable theoretical discussion on the possibility of fractional quantization of conductance in the absence of Landau levels formed by a quantizing…

Mesoscale and Nanoscale Physics · Physics 2019-03-05 S. Kumar , M. Pepper , S. N. Holmes , H. Montagu , Y. Gul , D. A. Ritchie , I. Farrer

Recent observations of the fractional anomalous quantum Hall effect in moir\'e materials have reignited the interest in fractional Chern insulators (FCIs). The chiral limit in which analytic Landau level-like single-particle states form an…

Strongly Correlated Electrons · Physics 2025-06-06 Hui Liu , Kang Yang , Ahmed Abouelkomsan , Zhao Liu , Emil J. Bergholtz

Strong interactions in Landau flat bands are known to stabilize correlated states that do not form in other types of flat bands. We report hallmarks of topological protection at the Landau level filling factor v=7/11 in a two-dimensional…

Mesoscale and Nanoscale Physics · Physics 2025-10-08 Waseem Hussain , Haoyun Huang , Loren N. Pfeiffer , Kenneth W. West , Kirk. W. Baldwin , Gábor A. Csáthy

We predict the emergence a state of matter with intertwined ferromagnetism, charge order and topology in fractionally filled moir\'e superlattice bands. Remarkably, these quantum anomalous Hall crystals exhibit a quantized integer Hall…

Mesoscale and Nanoscale Physics · Physics 2024-08-20 D. N. Sheng , Aidan P. Reddy , Ahmed Abouelkomsan , Emil J. Bergholtz , Liang Fu

We investigate numerically different phases that can occur at half filling in the lowest and the first excited Landau levels in wide-well twodimensional electron systems exposed to a perpendicular magnetic field. Within a twocomponent model…

Mesoscale and Nanoscale Physics · Physics 2015-12-16 N. Thiebaut , N. Regnault , M. O. Goerbig

The structure of fractional fillings of higher Landau levels including spin subbands is systematically derived for the first time. Using topology-type commensurability arguments for 2D charged system in the presence of strong quantizing…

General Physics · Physics 2014-08-21 Janusz Jacak , Lucjan Jacak

Magneto-transport measurements in a clean two-dimensional electron system confined to a wide GaAs quantum well reveal that, when the electrons occupy two electric subbands, the sequences of fractional quantum Hall states observed at high…

Mesoscale and Nanoscale Physics · Physics 2015-05-18 J. Shabani , Y. Liu , M. Shayegan

When electrons moving in two-dimensions (2D) are subjected to a strong uniform magnetic field, they form flat bands called Landau levels, which are the basis for the quantum Hall effect. Landau levels can also arise from pseudomagnetic…

Mesoscale and Nanoscale Physics · Physics 2025-05-14 Zheyu Cheng , Yi-jun Guan , Haoran Xue , Yong Ge , Ding Jia , Yang Long , Shou-qi Yuan , Hong-xiang Sun , Yidong Chong , Baile Zhang

The spectrum of charged particles in translation-invariant systems in a magnetic field is characterized by the Landau levels, which play a fundamental role in the thermodynamic and transport properties of solids. The topological nature and…

Mesoscale and Nanoscale Physics · Physics 2023-10-02 Isac Sahlberg , Moein N. Ivaki , Kim Pöyhönen , Teemu Ojanen

Fractional Chern insulators realize the remarkable physics of the fractional quantum Hall effect (FQHE) in crystalline systems with Chern bands. The lowest Landau level (LLL) is known to host the FQHE, but not all Chern bands are suitable…

Strongly Correlated Electrons · Physics 2024-04-22 Patrick J. Ledwith , Ashvin Vishwanath , Daniel E. Parker