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Energy band structure of the bilayer graphene superlattices with $\delta$-function magnetic barriers and zero average magnetic flux is studied within the four-band continuum model, using the transfer matrix method. The periodic magnetic…

Mesoscale and Nanoscale Physics · Physics 2014-09-29 C. Huy Pham , T. Thuong Nguyen , V. Lien Nguyen

We combined periodic ripples and electrostatic potentials to form curved graphene superlattices and studied the effects of space-dependent Fermi velocity induced from curvature on their electronic properties. With equal periods and…

Mesoscale and Nanoscale Physics · Physics 2021-06-29 Jianli Luan , Kaiyi Guo , Shangyang Li , Tianxing Ma , Li-Gang Wang , Hai-Qing Lin

We have investigated the Fock-Darwin states of the massless chiral fermions confined in a graphitic parabolic quantum dot. In the light of the Klein tunneling, we have analyzed the condition for confinement of the Dirac fermions in a…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Hong-Yi Chen , Vadim Apalkov , Tapash Chakraborty

The behavior of electrons in strained graphene is usually described using effective pseudomagnetic fields in a Dirac equation. Here we consider the particular case of a spatially constant strain. Our results indicate that lattice…

Mesoscale and Nanoscale Physics · Physics 2013-09-10 M. Oliva-Leyva , G. G. Naumis

We analyze bound modes of two-dimensional massless Dirac fermions confined within a hyperbolic secant potential, which provides a good fit for potential profiles of existing top-gated graphene structures. We show that bound states of both…

Mesoscale and Nanoscale Physics · Physics 2014-01-06 R. R. Hartmann , M. E. Portnoi

We review the energy spectrum and transport properties of several types of one- dimensional superlattices (SLs) on single-layer and bilayer graphene. In single-layer graphene, for certain SL parameters an electron beam incident on a SL is…

Mesoscale and Nanoscale Physics · Physics 2015-03-17 M. Barbier , P. Vasilopoulos , F. M. Peeters

We propose a tunable electronic band gap and zero-energy modes in periodic heterosubstrate-induced graphene superlattices. Interestingly, there is an approximate linear relation between the band gap and the proportion of inhomogeneous…

Materials Science · Physics 2016-05-04 Xiong Fan , Wenjun Huang , Tianxing Ma , Li-Gang 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

The electronic structure of a graphene superlattice composed by two periodic regions with different Fermi velocity, energy gap and electrostatic potential is investigated by using an effective Dirac-like Hamiltonian. It must be expected…

Materials Science · Physics 2015-04-07 Jonas R. F. Lima

The perfect transmission of charge carriers through potential barriers in graphene (Klein tunneling) is a direct consequence of the Dirac equation that governs the low-energy carrier dynamics. As a result, localized states do not exist in…

Artifical superlattice (SL) potentials have been employed extensively for band structure engineering of two-dimensional (2D) Dirac electron gas in graphene. While such engineered electronic band structures can modify optical or plasmonic…

Mesoscale and Nanoscale Physics · Physics 2022-03-29 Minwoo Jung , Gennady Shvets

In this review we focus on the effect of the Dirac nature of graphene quasiparticles on two separate aspects. The first of these involves transport across superconducting graphene junctions with barriers of thickness $d_0$ and arbitrary…

Strongly Correlated Electrons · Physics 2012-09-11 M. Maiti , K. Saha , K. Sengupta

Graphene-based superlattice (SL) formed by a periodic gap modulation is studied theoretically using a Dirac-type Hamiltonian. Analyzing the dispersion relation we have found that new Dirac points arise in the electronic spectrum under…

Mesoscale and Nanoscale Physics · Physics 2015-06-11 G. M. Maksimova , E. S. Azarova , A. V. Telezhnikov , V. A. Burdov

Massless Dirac particles cannot be confined by an electrostatic potential. This is a problem for making graphene quantum dots but confinement can be achieved with a magnetic field and here, general conditions for confined and deconfined…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 G. Giavaras , P. A. Maksym , M. Roy

The recent discovery of methods to isolate graphene, a one-atom-thick layer of crystalline carbon, has raised the possibility of a new class of nano-electronics devices based on the extraordinary electrical transport and unusual physical…

Mesoscale and Nanoscale Physics · Physics 2008-10-02 Xu Du , Ivan Skachko , Anthony Barker , Eva Y. Andrei

A graphene superlattice is formed by a one-dimensional periodic potential and is characterized by the emergence of new Dirac points in the electronic structure. The group velocity of graphene's massless Dirac fermions at the new points is…

Motivated by recent proposals on strain-engineering of graphene electronic circuits we calculate conductivity, shot-noise and the density of states in periodically deformed graphene. We provide the solution to the Dirac-Kronig-Penney model,…

Mesoscale and Nanoscale Physics · Physics 2010-10-13 S. Gattenloehner , W. Belzig , M. Titov

The role of defect-induced zero-energy modes on charge transport in graphene is investigated using Kubo and Landauer transport calculations. By tuning the density of random distributions of monovacancies either equally populating the two…

Mesoscale and Nanoscale Physics · Physics 2013-05-13 Alessandro Cresti , Frank Ortmann , Thibaud Louvet , Dinh Van Tuan , Stephan Roche

The excitations in graphene and some other materials are described by two-dimensional massless Dirac equation with applied external potential of some kind. Solutions of this zero energy equation are built analytically for a wide class of…

Mesoscale and Nanoscale Physics · Physics 2018-11-14 M. V. Ioffe , D. N. Nishnianidze

We investigate the effect of a periodic potential on the electronic states and conductance of graphene. It is demonstrated that for a cosine potential $V(x)=V_0\cos(G_0x)$, new zero energy states emerge whenever $J_0(\frac {2V_0}{\hbar v_F…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 L. Brey , H. A. Fertig