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Related papers: Programmable Dirac masses in hybrid moir\'e--1D su…

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Dirac semimetals, the materials featured with discrete linearly crossing points (called Dirac points) between four bands, are critical states of topologically distinct phases. Such gapless topological states have been accomplished by a…

Materials Science · Physics 2020-01-20 Xiangxi Cai , Liping Ye , Chunyin Qiu , Meng Xiao , Rui Yu , Manzhu Ke , Zhengyou Liu

We demonstrate a generic mechanism to realize topological flat minibands by confining massive Dirac fermions in a periodic moir\'e potential, which can be achieved in a heterobilayer of transition metal dichalcogenides. We show that the…

Mesoscale and Nanoscale Physics · Physics 2022-10-28 Ying Su , Heqiu Li , Chuanwei Zhang , Kai Sun , Shi-Zeng Lin

We find a systematic reappearance of massive Dirac features at the edges of consecutive minibands formed at magnetic fields B_{p/q}= p\phi_0/(qS) providing rational magnetic flux through a unit cell of the moire superlattice created by a…

Mesoscale and Nanoscale Physics · Physics 2014-02-10 Xi Chen , J. R. Wallbank , A. A. Patel , M. Mucha-Kruczynski , E. McCann , V. I. Fal'ko

Relativistic Dirac fermions are ubiquitous in condensed matter physics. Their mass is proportional to the material energy gap and the ability to control and tune the mass has become an essential tool to engineer quantum phenomena that mimic…

Mesoscale and Nanoscale Physics · Physics 2018-08-13 G. Krizman , B. A. Assaf , T. Phuphachong , G. Bauer , G. Springholz , G. Bastard , R. Ferreira , L. A. de Vaulchier , Y. Guldner

Strong Coulomb repulsion is predicted to open a many-body charge gap at the Dirac point of graphene, transforming the semimetal into a Mott insulator. However, this correlated insulating phase has remained inaccessible in pristine graphene,…

The recent discovery of Dirac semimetals represents a new achievement in our fundamental understanding of topological states of matter. Due to their topological surface states, high mobility, and exotic properties associated with bulk Dirac…

Mesoscale and Nanoscale Physics · Physics 2015-02-13 Xianbo Xiao , Shengyuan A. Yang , Zhengfang Liu , Huili Li , Guanghui Zhou

We formulate a low energy effective Hamiltonian to study superlattices in bilayer graphene (BLG) using a minimal model which supports quadratic band touching points. We show that a one dimensional (1D) periodic modulation of the chemical…

Mesoscale and Nanoscale Physics · Physics 2011-08-23 Matthew Killi , Si Wu , Arun Paramekanti

High mobility single and few-layer graphene sheets are in many ways attractive as nanoelectronic circuit hosts but lack energy gaps, which are essential to the operation of field-effect transistors. One of the methods used to create gaps in…

Mesoscale and Nanoscale Physics · Physics 2018-12-26 Hakseong Kim , Nicolas Leconte , Bheema L. Chittari , Kenji Watanabe , Takashi Taniguchi , Allan H. MacDonald , Jeil Jung , Suyong Jung

Mirror-symmetric magic-angle twisted trilayer graphene (MATTG) hosts flat electronic bands close to zero energy, and has been recently shown to exhibit abundant correlated quantum phases with flexible electrical tunability. However studying…

Mesoscale and Nanoscale Physics · Physics 2023-03-22 Cheng Shen , Patrick J. Ledwith , Kenji Watanabe , Takashi Taniguchi , Eslam Khalaf , Ashvin Vishwanath , Dmitri K. Efetov

Lateral superlattices have attracted major interest as this may allow one to modify spectra of two dimensional electron systems and, ultimately, create materials with tailored electronic properties. Previously, it proved difficult to…

Inspired by the rich physics of twisted 2D bilayer moir\'{e} systems, we study Coulomb interacting systems subjected to two overlapping finite 1D lattice potentials of unequal periods through exact numerical diagonalization. Unmatching…

Mesoscale and Nanoscale Physics · Physics 2021-01-27 DinhDuy Vu , S. Das Sarma

Quantum materials that host a flat band, such as pseudospin-1 lattices and magic-angle twisted bilayer graphene, can exhibit drastically new physical phenomena including unconventional superconductivity, orbital ferromagnetism, and Chern…

Mesoscale and Nanoscale Physics · Physics 2020-07-01 Hong-Ya Xu , Ying-Cheng Lai

Quite recently a novel variety of unconventional fourfold linear band degeneracy points has been discovered in certain condensed-matter systems. Contrary to the standard 3-D Dirac monopoles, these quadruple points referred to as the…

Optics · Physics 2019-12-17 Mengying Hu , Kun Ding , Tong Qiao , Xi Jiang , Qiang Wang , Shining Zhu , Hui Liu

I study the internal structure of the Dirac magnetic monopole in a deconstructed $U(1)$ gauge theory. The deconstructed $U(1)$ gauge theory has a product $U(1)^N$ gauge group, which breaks down to the diagonal $U(1)_{\mathrm{diag}}$ gauge…

High Energy Physics - Theory · Physics 2025-09-12 Kazuyuki Furuuchi

We study a Dirac Harper model for moir\'e bilayer superlattices where layer antisymmetric strain periodically modulates the interlayer coupling between two honeycomb lattices in one spatial dimension. Discrete and continuum formulations of…

Mesoscale and Nanoscale Physics · Physics 2020-10-21 Abigail Timmel , E. J. Mele

We develop a theory of interaction effects in graphene superlattices, where tunable superlattice periodicity can be used as a knob to control the gap at the Dirac point. Applied to graphene on hexa-boron-nitride (G/h-BN), our theory…

Mesoscale and Nanoscale Physics · Physics 2013-12-31 Justin C. W. Song , Andrey V. Shytov , Leonid S. Levitov

We study the electronic and transport properties of a graphene-based superlattice theoretically by using an effective Dirac equation. The superlattice consists of a periodic potential applied on a single-layer graphene deposited on a…

Mesoscale and Nanoscale Physics · Physics 2015-02-26 Jonas R. F. Lima

The Lieb lattice is one of the simplest lattices that exhibits both linear Dirac-like and flat topological electronic bands. We propose to further tailor its electronic properties through periodic 1D electrostatic superlattices (SLs),…

Mesoscale and Nanoscale Physics · Physics 2025-02-05 Dylan Jones , Marcin Mucha-Kruczynski , Adelina Ilie , Lucian Covaci

We have studied the electronic properties in aperiodic graphene superlattices of Thue-Morse sequence. Although the structure is aperiodic, an unusual Dirac point (DP) does exist and its location is exactly at the position of the…

Mesoscale and Nanoscale Physics · Physics 2012-06-28 Tianxing Ma , Chun Liang , Li-Gang Wang , Hai-Qing Lin

Non-symmorphic symmetries protect Dirac nodal lines and cones in lattice systems. Here, we investigate the spectral properties of a two-dimensional lattice belonging to a non-symmorphic group. Specifically, we look at the herringbone…

Mesoscale and Nanoscale Physics · Physics 2023-03-09 M. A. J. Herrera , D. Bercioux