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Related papers: Chiral Tunnelling in Twisted Graphene Bilayer

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It is supposed the existence of a curved graphene sheet with the geometry of a Bour surface $B_{n}$, such as the catenoid (or helicoid), $B_{0}$, and the classical Enneper surface, $B_{2}$, among others. In particular, in this work, the…

Mesoscale and Nanoscale Physics · Physics 2022-07-13 Víctor A. González-Domínguez , Juan A Reyes-Nava , Pavel Castro-Villarreal

Klein's paradox refers to the transmission of a relativistic particle through a high potential barrier. Although it has a simple resolution in terms of particle-to-antiparticle tunneling (Klein tunneling), debates on its physical meaning…

Mesoscale and Nanoscale Physics · Physics 2024-03-19 Keiji Nakatsugawa , Xiao Hu

We investigate the unusual features of the quantum transport in gapped monolayer graphene, which is in a pseudospin symmetry-broken state with a net perpendicular pseudomagnetization. Using these pseudoferromagnets (PFs), we propose a…

Mesoscale and Nanoscale Physics · Physics 2013-08-20 Leyla Majidi , Malek Zareyan

We demonstrate a tunneling and rectification behavior in bilayer graphene. A stepped dielectric top gate creates a spatially modulated electric field, which opens the band gap in the graphene and produces an insulating region at the p-n…

Mesoscale and Nanoscale Physics · Physics 2011-12-19 Hisao Miyazaki , Michael Lee , Song-Lin Li , Hidefumi Hiura , Kazuhito Tsukagoshi , Akinobu Kanda

We study the transmission through single and double ferromagnetic barriers on the surface of a topological insulator. By adjusting the gate voltage and magnetization oreintation, the ferromagnetic barrier can be tuned into various…

Mesoscale and Nanoscale Physics · Physics 2009-09-03 Jinhua Gao , Wei-Qiang Chen , Xiao-Yong Feng , X. C. Xie , Fu-Chun Zhang

Strong interaction between electrons in two-dimensional systems in the presence of a high magnetic field gives rise to fractional quantum Hall states that host quasiparticles with fractional charge and fractional exchange statistics. Here,…

Transport through potential barriers in graphene is investigated using a set of metallic gates capacitively coupled to graphene to modulate the potential landscape. When a gate-induced potential step is steep enough, disorder becomes less…

Mesoscale and Nanoscale Physics · Physics 2009-01-18 N. Stander , B. Huard , D. Goldhaber-Gordon

Manipulating the circular polarization of light is of great importance in chemistry and biology, as chiral molecules exhibit different physiological properties when exposed to different circularly polarized waves. Here we suggest a…

Optics · Physics 2023-07-19 Tuo Chen , Sailing He

Moir\'e flatbands, occurring, e.g., in twisted bilayer graphene at magic angles, have attracted ample interest due to their high degree of experimental tunability and the intriguing possibility of generating novel strongly interacting…

Mesoscale and Nanoscale Physics · Physics 2020-03-17 Ahmed Abouelkomsan , Zhao Liu , Emil J. Bergholtz

The energy spectrum of graphene sheet with a single barrier structure having a time periodic oscillating height and subjected to magnetic field is analyzed. The corresponding transmission is studied as function of the obtained energy and…

Mesoscale and Nanoscale Physics · Physics 2015-06-18 Ahmed Jellal , Miloud Mekkaoui , El Bouazzaoui Choubabi , Hocine Bahlouli

It is shown that chiral plasmons, characterized by a longitudinal magnetic moment accompanying the longitudinal charge plasmon, lead to electromagnetic near-fields that are also chiral. For twisted bilayer graphene, we estimate that the…

Mesoscale and Nanoscale Physics · Physics 2021-09-21 T. Stauber , T. Low , G. Gómez-Santos

Electronic structures and their Landau quantizations in twisted graphene bilayer and trilayer are investigated using scanning tunnelling microscopy and spectroscopy. In the twisted trilayer, the top graphene layer and second layer are AB…

Mesoscale and Nanoscale Physics · Physics 2015-01-09 Long-Jing Yin , Jia-Bin Qiao , Wei Yan , Rui Xu , Rui-Fen Dou , Jia-Cai Nie , Lin He

Starting from the strong-coupling limit of an extended Hubbard model, we develop a spin-fermion theory to study the insulating phase and pairing symmetry of the superconducting phase in twisted bilayer graphene. Assuming that the insulating…

Superconductivity · Physics 2020-05-20 Xingyu Gu , Chuan Chen , Jia Ning Leaw , Evan Laksono , Vitor M. Pereira , Giovanni Vignale , Shaffique Adam

We study the tunneling effect of Dirac fermions in a graphene sheet by introducing a potential barrier in a region of width $D$ exposed to laser field. This sheet is placed on a boron nitride/ferromagnetic substrate such as cobalt or…

Mesoscale and Nanoscale Physics · Physics 2025-03-06 Rachid El Aitouni , Ahmed Jellal , Pablo Díaz , David Laroze

In the case of the strongly deformed graphene, gapless graphene may turn to gapped graphene at the critical deformation. We find that, like semi-massless fermions, electrons in the deformed graphene, at the critical point, mimic the…

Mesoscale and Nanoscale Physics · Physics 2010-09-28 Bumned Soodchomshom

The wavefunction of a massless fermion consists of two chiralities, left-handed and right-handed, which are eigenstates of the chiral operator. The theory of weak interactions of elementally particle physics is not symmetric about the two…

Mesoscale and Nanoscale Physics · Physics 2014-11-21 Ken-ichi Sasaki , Riichiro Saito , Mildred S. Dresselhaus , Katsunori Wakabayashi , Toshiaki Enoki

Ripples in pristine freestanding graphene naturally orient themselves in an array that is alternately curved-up and curved-down; maintaining an average height of zero. Using scanning tunneling microscopy (STM) to apply a local force, the…

Mesoscale and Nanoscale Physics · Physics 2015-06-23 J. K. Schoelz , P. Xu , V. Meunier , P. Kumar , M. Neek-Amal , P. M. Thibado , F. M. Peeters

Moir\'e systems have emerged in recent years as a rich platform to study strong correlations. Here, we will discuss a simple, experimentally feasible setup based on periodically strained graphene that reproduces several key aspects of…

Mesoscale and Nanoscale Physics · Physics 2022-11-03 Qiang Gao , Junkai Dong , Patrick Ledwith , Daniel Parker , Eslam Khalaf

Twisted bilayer graphene (TBG) near the magic twist angle of $\sim1.1^{o}$ exhibits a rich phase diagram. However, the interplay between different phases and their dependence on twist angle is still elusive. Here, we explore the stability…

Electrostatic confinement of charge carriers in graphene is governed by Klein tunneling, a relativistic quantum process in which particle-hole transmutation leads to unusual anisotropic transmission at pn junction boundaries. Reflection and…