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We report an efficient technique to induce gate-tunable two-dimensional superlattices in graphene by the combined action of a back gate and a few-layer graphene patterned bottom gate complementary to existing methods. The patterned gates in…

Superlattice potential modulation can produce flat minibands in Bernal-stacked bilayer graphene. In this work we study how band topology and interaction-induced symmetry-broken phases in this system are controlled by tuning the displacement…

Mesoscale and Nanoscale Physics · Physics 2024-07-04 Yongxin Zeng , Tobias M. R. Wolf , Chunli Huang , Nemin Wei , Sayed Ali Akbar Ghorashi , Allan H. MacDonald , Jennifer Cano

Topological materials may exhibit Hall-like currents flowing transversely to the applied electric field even in the absence of a magnetic field. In graphene superlattices, which have broken inversion symmetry, topological currents…

A scalable tight-binding model is applied for large-scale quantum transport calculations in clean graphene subject to electrostatic superlattice potentials, including two types of graphene superlattices: moir\'e patterns due to the stacking…

Mesoscale and Nanoscale Physics · Physics 2020-04-29 Szu-Chao Chen , Rainer Kraft , Romain Danneau , Klaus Richter , Ming-Hao Liu

We show that, if graphene is subjected to the potential from an external superlattice, a band gap develops at the Dirac point provided the superlattice potential has broken inversion symmetry. As a numerical example, we calculate the band…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 Rakesh P Tiwari , D. Stroud

We predict the coexistence of tunneling spin and valley Hall effects when electrons in graphene coherently transmit through a barrier with the broken inversion symmetry and proximity-induced spin-orbit coupling. Due to the rotation of the…

Mesoscale and Nanoscale Physics · Physics 2025-02-20 W. Zeng

We provide a critical discussion concerning the claim of topological valley currents, driven by a global Berry curvature and valley Hall effect proposed in recent literature. After pointing out a major inconsistency of the theoretical…

Mesoscale and Nanoscale Physics · Physics 2021-11-17 Stephan Roche , Stephen R. Power , Branislav K. Nikolić , José Hugo García , Antti-Pekka Jauho

Flat bands emerging in buckled monolayer graphene superlattices have been recently shown to realize correlated states analogous to those observed in twisted graphene multilayers. Here, we demonstrate the emergence of valley topology driven…

Mesoscale and Nanoscale Physics · Physics 2021-06-30 Antonio L. R. Manesco , Jose L. Lado

Using the B\"{u}ttiker-Landauer formulation of transport theory in the linear response regime, the valley currents and non-local resistances of bilayer graphene nanostructures with broken inversion symmetry are calculated. It is shown that…

Mesoscale and Nanoscale Physics · Physics 2017-11-16 Mohammadhadi Azari , George Kirczenow

Valley pseudospin, the quantum degree of freedom characterizing the degenerate valleys in energy bands, is a distinct feature of two-dimensional Dirac materials. Similar to spin, the valley pseudospin is spanned by a time reversal pair of…

Mesoscale and Nanoscale Physics · Physics 2016-01-20 Mengqiao Sui , Guorui Chen , Liguo Ma , Wenyu Shan , Dai Tian , Kenji Watanabe , Takashi Taniguchi , Xiaofeng Jin , Wang Yao , Di Xiao , Yuanbo Zhang

Recent introduction of superlattice potentials has opened new avenues for engineering tunable electronic band structures featuring topologically nontrivial moir\'{e}-like bands. Here we consider optoelectronic properties of Bernal-stacked…

Mesoscale and Nanoscale Physics · Physics 2025-12-29 Nabil Atlam , Swati Chaudhary , Arpit Raj , Matthew Matzelle , Barun Ghosh , Gregory A. Fiete , Arun Bansil

Superlattice in graphene generates extra Dirac points in the band structure and their number depends on the superlattice potential strength. Here, we have created a lateral superlattice in a graphene device with a tunable barrier height…

Though the observation of the quantum anomalous Hall effect and nonlocal transport response reveals nontrivial band topology governed by the Berry curvature in twisted bilayer graphene, some recent works reported nonlinear Hall signals in…

Mesoscale and Nanoscale Physics · Physics 2023-08-16 Meizhen Huang , Zefei Wu , Xu Zhang , Xuemeng Feng , Zishu Zhou , Shi Wang , Yong Chen , Chun Cheng , Kai Sun , Zi Yang Meng , Ning Wang

Dirac-electronic tunneling and nonlinear transport properties with both finite and zero energy bandgap are investigated for graphene with a tilted potential barrier under a bias. For validation, results from a finite-difference based…

Mesoscale and Nanoscale Physics · Physics 2020-04-01 Farhana Anwar , Andrii Iurov , Danhong Huang , Godfrey Gumbs , Ashwani Sharma

We numerically investigate the electronic transport properties of graphene nanoribbons and carbon nanotubes with inter-valley coupling, e.g., in \sqrt{3}N \times \sqrt{3}N and 3N \times 3N superlattices. By taking the \sqrt{3} \times…

Mesoscale and Nanoscale Physics · Physics 2017-01-04 Fuming Xu , Zhizhou Yu , Yafei Ren , Bin Wang , Yadong Wei , Zhenhua Qiao

The electronic transport properties of graphene-based superlattice structures are investigated. A graphene-based modulation-doped superlattice structure geometry is proposed and consist of periodically arranged alternate layers:…

Mesoscale and Nanoscale Physics · Physics 2013-11-25 Dima Bolmatov , Chung-Yu Mou

Realizations of some topological phases in two-dimensional systems rely on the challenge of jointly incorporating spin-orbit and magnetic exchange interactions. Here, we predict the formation and control of a fully valley-polarized quantum…

Mesoscale and Nanoscale Physics · Physics 2021-10-25 Marc Vila , Jose H. Garcia , Stephan Roche

Berry curvature is analogous to magnetic field but in momentum space and is commonly present in materials with non-trivial quantum geometry. It endows Bloch electrons with transverse anomalous velocities to produce Hall-like currents even…

Growth of graphene on monolayer transition-metal dichalcogenides presents opening on band gap and giant spin-orbit coupling which paves the way to achieve a useful hybrid structure for electronics and spintronics applications. Increase of…

Mesoscale and Nanoscale Physics · Physics 2019-01-29 S. F. Ebadzadeh , H. Goudarzi , M. Khezerlou

The electronic transmission and conductance of a gapped graphene superlattice were calculated by means of the transfer-matrix method. The system that we study consists of a sequence of electron-doped graphene as wells and hole-doped…

Mesoscale and Nanoscale Physics · Physics 2015-05-14 M. Esmailpour , A. Esmailpour , Reza Asgari , E. Elahi , M. R. Rahimi Tabar
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