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Related papers: Realization of Topological Mott Insulator in a Twi…

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The rich phenomenology of twisted bilayer graphene (TBG) near the magic angle is believed to arise from electron correlations in topological flat bands. An unbiased approach to this problem is highly desirable, but also particularly…

Strongly Correlated Electrons · Physics 2021-09-28 Johannes S. Hofmann , Eslam Khalaf , Ashvin Vishwanath , Erez Berg , Jong Yeon Lee

At partial fillings of its flat electronic bands, magic-angle twisted bilayer graphene (MATBG) hosts a rich variety of competing correlated phases that show sample to sample variations. Divergent phase diagrams in MATBG are often attributed…

Mesoscale and Nanoscale Physics · Physics 2023-07-12 Dillon Wong , Kevin P. Nuckolls , Myungchul Oh , Ryan L. Lee , Kenji Watanabe , Takashi Taniguchi , Ali Yazdani

We develop a model to describe the mixed valence regime in magic-angle twisted bilayer graphene (MATBG) using the recently developed heavy-fermion framework. By employing the large-$N$ slave-boson approach, we derive the self-consistent…

Superconductivity · Physics 2024-07-16 Yantao Li , Benjamin M. Fregoso , Maxim Dzero

While the recent advances in topology have led to a classification scheme for electronic bands described by the standard theory of metals, a similar scheme has not emerged for strongly correlated systems such as Mott insulators in which a…

Strongly Correlated Electrons · Physics 2023-04-18 Peizhi Mai , Benjamin E. Feldman , Philip W. Phillips

Magic angle twisted bilayer graphene (MATBG) hosts narrow moir\'e bands with meV-scale energy splittings, making its correlated phases sensitive to both material parameters and modeling choices in low-energy downfolding. We develop an ab…

Strongly Correlated Electrons · Physics 2026-03-12 Raehyun Kim , Woochang Kim , Kevin D. Stubbs , Steven G. Louie , Lin Lin

We show that gated bilayer graphene hosts a strong topological insulator (TI) phase in the presence of Rashba spin-orbit (SO) coupling. We find that gated bilayer graphene under preserved time-reversal symmetry is a quantum valley Hall…

Materials Science · Physics 2011-12-15 Zhenhua Qiao , Wang-Kong Tse , Hua Jiang , Yugui Yao , Qian Niu

We report a magneto-induced topological phase transition in inverted InAs/GaSb bilayers from a quantum spin Hall insulator to a normal insulator. We utilize a dual-gated Corbino device in which the degree of band inversion, or equivalently…

Mesoscale and Nanoscale Physics · Physics 2024-12-24 Zhongdong Han , Tingxin Li , Long Zhang , Rui-Rui Du

The search for new realization of topologically protected edge states is an active area of research. We show that a tilt boundary in gated multi-layer graphene supports topologically protected gapless kink states, associated with quantum…

Mesoscale and Nanoscale Physics · Physics 2013-06-27 Abolhassan Vaezi , Yufeng Liang , Darryl H. Ngai , Li Yang , Eun-Ah Kim

The long wavelength moir\'e superlattices in twisted 2D structures have emerged as a highly tunable platform for strongly correlated electron physics. We study the moir\'e bands in twisted transition metal dichalcogenide homobilayers,…

Mesoscale and Nanoscale Physics · Physics 2021-11-19 Trithep Devakul , Valentin Crépel , Yang Zhang , Liang Fu

At partial filling of a flat band, strong electronic interactions may favor gapped states harboring emergent topology with quantized Hall conductivity. Emergent topological states have been found in partially filled Landau levels and…

We present a combined experimental and theoretical study of twisted double bilayer graphene with twist angles between 1{\deg} and 1.35{\deg}. Consistent with moir\'e band structure calculations, we observe insulators at integer moir\'e band…

Mesoscale and Nanoscale Physics · Physics 2019-11-25 G. William Burg , Jihang Zhu , Takashi Taniguchi , Kenji Watanabe , Allan H. MacDonald , Emanuel Tutuc

In this work we consider a system of spinless fermions with nearest and next-to-nearest neighbor repulsive Hubbard interactions on a honeycomb lattice, and propose and analyze a realistic scheme for analog quantum simulation of this model…

Strongly Correlated Electrons · Physics 2012-12-13 A. Dauphin , M. Müller , M. A. Martin-Delgado

Using dynamical mean-field theory and exact diagonalization we study the phase diagram of the repulsive Haldane-Hubbard model, varying the interaction strength and the sublattice potential difference. In addition to the quantum Hall phase…

Quantum Gases · Physics 2016-06-08 Tuomas I. Vanhala , Topi Siro , Long Liang , Matthias Troyer , Ari Harju , Päivi Törmä

Research on graphene has revealed remarkable phenomena arising in the honeycomb lattice. However, the quantum spin Hall effect predicted at the K point could not be observed in graphene and other honeycomb structures of light elements due…

Mesoscale and Nanoscale Physics · Physics 2015-03-23 W. Beugeling , E. Kalesaki , C. Delerue , Y. -M. Niquet , D. Vanmaekelbergh , C. Morais Smith

The rich physics of magic angle twisted bilayer graphene (TBG) results from the Coulomb interactions of electrons in flat bands of non-trivial topology. While the bands' dispersion is well characterized, accessing their topology remains an…

Mesoscale and Nanoscale Physics · Physics 2026-03-10 F. Mesple , P. Mallet , G. Trambly de Laissardière , C. Dutreix , G. Lapertot , J-Y. Veuillen , V. T. Renard

We present a theoretical study of an interaction-driven quantum phase diagram of twisted bilayer MoTe$_2$ at hole filling factor $\nu_h=1$ as a function of twist angle $\theta$ and layer potential difference $V_z$, where $V_z$ is generated…

Mesoscale and Nanoscale Physics · Physics 2024-01-19 Bohao Li , Wen-Xuan Qiu , Fengcheng Wu

Moir\'e transition metal dichalcogenide (TMD) materials provide an ideal playground for studying the combined interplay of strong interactions and band-topology over a range of electronic fillings. Here we investigate the panoply of…

Strongly Correlated Electrons · Physics 2024-11-22 Juan Felipe Mendez-Valderrama , Sunghoon Kim , Debanjan Chowdhury

Moir\'e lattices provide a highly tunable platform for exploring the interplay between electronic correlations and band topology. Introducing a second moir\'e pattern extends this paradigm: interference between the two moir\'e patterns…

Electron interactions in quantum materials fundamentally shape their energy bands and, with them, the material's most intriguing quantum phases. Magic angle twisted bilayer graphene (MATBG) has emerged as a model system, where flat bands…

Mesoscale and Nanoscale Physics · Physics 2025-06-27 J. Xiao , A. Inbar , J. Birkbeck , N. Gershon , Y. Zamir , T. Taniguchi , K. Watanabe , E. Berg , S. Ilani

The electronic structure at the interface between a topological band insulator and a Mott insulator is studied within layer dynamical mean field theory. To represent the bulk phases of these systems, we use the generalized…

Strongly Correlated Electrons · Physics 2015-06-22 H. Ishida , A. Liebsch