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Related papers: Topological phase transitions in twisted bilayer g…

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The discoveries of numerous exciting phenomena in twisted bilayer graphene (TBG) are stimulating significant investigations on moir\'e structures that possess a tunable moir\'e potential. Optical response can provide insights into the…

We investigate the mesoscopic transport through a twisted bilayer graphene (TBG) consisting of a clean graphene nanoribbon on the bottom and a disordered graphene disc on the top. We show that, with strong top-layer disorder the…

Mesoscale and Nanoscale Physics · Physics 2024-02-20 Zhe Hou , Ya-Yun Hu , Guang-Wen Yang

We systematically investigate how static symmetry-breaking perturbations and dynamic Floquet terms via a polarized light manipulate the topological phase transitions in the two-dimensional quadratic-band-crossing-point (QBCP) materials. The…

Mesoscale and Nanoscale Physics · Physics 2026-05-27 Wen-Hao Bian , Jing Wang

We present a theoretical study of the local optical conductivity, plasmon spectra, and thermoelectric properties of twisted bilayer graphene (TBG) at different filling factors and twist angles $\theta$. Our calculations are based on the…

Mesoscale and Nanoscale Physics · Physics 2020-09-04 Pietro Novelli , Iacopo Torre , Frank H. L. Koppens , Fabio Taddei , Marco Polini

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…

Twisted homobilayer transition metal dichalcogenide (TMD) offers a versatile platform for exploring band topology, interaction-driven phases, and magnetic orders. We study the interaction-driven phases in twisted TMD homobilayers and their…

Strongly Correlated Electrons · Physics 2024-09-12 Taige Wang , Trithep Devakul , Michael P. Zaletel , Liang Fu

A series of recent experimental works on twisted MoTe$_2$ homobilayers have unveiled an abundance of exotic states in this system. Valley-polarized quantum anomalous Hall states have been identified at hole doping of $\nu = -1$, and the…

Mesoscale and Nanoscale Physics · Physics 2024-04-16 Xiaoyu Liu , Chong Wang , Xiao-Wei Zhang , Ting Cao , Di Xiao

Electrons residing in flat-band system can play a vital role in triggering spectacular phenomenology due to relatively large interactions and spontaneous breaking of different degeneracies. In this work we demonstrate chirally twisted…

We show that bilayer graphene in the presence of a 2D superlattice potential provides a highly tunable setup that can realize a variety of flat band phenomena. We focus on two regimes: (i) topological flat bands with non-zero Chern numbers,…

Mesoscale and Nanoscale Physics · Physics 2023-06-16 Sayed Ali Akbar Ghorashi , Aaron Dunbrack , Ahmed Abouelkomsan , Jiacheng Sun , Xu Du , Jennifer Cano

Two monolayers of graphene twisted by a small `magic' angle exhibit nearly flat bands leading to correlated electronic states and superconductivity, whose precise nature including possible broken symmetries, remain under debate. Here we…

Strongly Correlated Electrons · Physics 2019-12-13 Jong Yeon Lee , Eslam Khalaf , Shang Liu , Xiaomeng Liu , Zeyu Hao , Philip Kim , Ashvin Vishwanath

The existence of strong trigonal warping around the K point for the low energy electronic states in multilayer (N$\geq$2) graphene films and graphite is well established. It is responsible for phenomena such as Lifshitz transitions and…

We study the electronic and topological properties of fully relaxed twisted bilayer (TBG) and double bilayer (TDBG) graphene under perpendicular pressure. An approach has been proposed to obtain the equilibrium in-plane structural…

Mesoscale and Nanoscale Physics · Physics 2020-07-20 Xianqing Lin , Haotian Zhu , Jun Ni

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

Interlayer sliding, together with twist angle, is a crucial parameter that defines the atomic registry and thus determines the properties of two-dimensional (2D) material homobilayers. Here, we theoretically demonstrate that controlled…

Mesoscale and Nanoscale Physics · Physics 2025-11-18 Jie Pan , Huanhuan Wang , Lin Zou , Xiaoyu Wang , Lihao Zhang , Xueyan Dong , Haibo Xie , Yi Ding , Yuze Zhang , Takashi Taniguchi , Kenji Watanabe , Shuxi Wang , Zhe Wang

We study twisted bilayer MoTe$_2$ systems at fractional fillings of the lowest hole band under an applied out-of-plane displacement field. By employing exact diagonalization in finite-size systems, we systematically map out the ground state…

Mesoscale and Nanoscale Physics · Physics 2024-09-24 Prakash Sharma , Yang Peng , D. N. Sheng

Higher-order topological insulators are newly proposed topological phases of matter, whose bulk topology manifests as localized modes at two- or higher-dimensional lower boundaries. In this work, we propose the twisted bilayer graphenes…

Mesoscale and Nanoscale Physics · Physics 2019-11-27 Moon Jip Park , Youngkuk Kim , Gil Young Cho , SungBin Lee

The relative strength of different proximity spin-orbit couplings in graphene on transition metal dichalcogenides (TMDC) can be tuned via the metal composition in the TMDC layer. While Gr/MoSe$_2$, has a normal gap, proximity to WSe$_2$…

Mesoscale and Nanoscale Physics · Physics 2023-07-31 Zahra Khatibi , Stephen R. Power

Electron collimation via a graphene pn-junction allows electrostatic control of ballistic electron trajectories akin to that of an optical circuit. Similar manipulation of novel correlated electronic phases in twisted-bilayer graphene…

Mesoscale and Nanoscale Physics · Physics 2024-04-02 Wei Ren , Xi Zhang , Ziyan Zhu , Moosa Khan , Kenji Watanabe , Takashi Taniguchi , Efthimios Kaxiras , Mitchell Luskin , Ke Wang

To date, almost all of the discussions on topological insulators (TIs) have focused on two- and three-dimensional systems. One-dimensional (1D) TIs manifested in real materials, in which localized spin states may exist at the end or near…

Mesoscale and Nanoscale Physics · Physics 2018-10-18 Kuan-Sen Lin , Mei-Yin Chou

Twisted bilayer graphene (tBLG) has recently emerged as a platform for hosting correlated phenomena, owing to the exceptionally flat band dispersion that results near interlayer twist angle $\theta\approx1.1^\circ$. At low temperature a…

Strongly Correlated Electrons · Physics 2019-10-03 H. Polshyn , M. Yankowitz , S. Chen , Y. Zhang , K. Watanabe , T. Taniguchi , C. R. Dean , A. F. Young