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Modulation of electronic states in two-dimensional (2D) materials can be achieved by using in-plane variations of the band gap or the average potential in lateral quantum structures. In the atomic configurations with hexagonal symmetry,…

Mesoscale and Nanoscale Physics · Physics 2016-08-10 Feng-Wu Chen , Mei-Yin Chou , Yiing-Rei Chen , Yu-Shu Wu

It is shown that potential barriers in bilayer graphene (BLG) and monolayer transition metal dichalcogenides (TMDs) can split a valley unpolarized incident current into reflected and transmitted currents with opposite valley polarization.…

Mesoscale and Nanoscale Physics · Physics 2021-10-04 P. A. Maksym , H. Aoki

We propose a device for the generation of valley polarized electronic current in bilayer graphene. By analyzing the response of this material to intense terahertz frequency light in the presence of a transverse electric field, we…

Mesoscale and Nanoscale Physics · Physics 2009-08-20 D. S. L. Abergel , Tapash Chakraborty

Optical polarizing devices exploiting graphene embedded in waveguides have been demonstrated in the literature recently and both the TE- and TM-pass behaviors were reported. The determination of the passing polarization is usually…

Optics · Physics 2015-10-08 Rafael E. P. de Oliveira , Christiano J. S. de Matos

Graphene on hBN (G/hBN) has a long period moir\'{e} superstructure owing to the lattice mismatch between two materials. Long periodic potential caused by the moir\'{e} superstructure induces modulation of electronic properties of the…

Mesoscale and Nanoscale Physics · Physics 2022-08-11 Keisuke Nakagahara , Katsunori Wakabayashi

The aim of this work is to describe the electronic properties of graphene in a constant magnetic field in the long wavelength approximation with random binary disorder, by solving the Soven equation self-consistently. Density of state…

Mesoscale and Nanoscale Physics · Physics 2015-03-03 Juan Sebastian Ardenghi , Pablo Bechthold , Estela Gonzalez , Paula Jasen , Alfredo Juan

In this work we investigate the effects of a Fermi velocity modulation in a valley filter in graphene created by a combination of a magnetic and electric barrier. With the effective Dirac equation of the system, we use the transfer matrix…

Mesoscale and Nanoscale Physics · Physics 2020-01-22 A. R. S. Lins , Jonas R. F. Lima

We present a single barrier system to generate pure valley-polarized current in monolayer graphene. A uniaxial strain is applied within the barrier region, which is delineated by localized magnetic field created by ferromagnetic stripes at…

Mesoscale and Nanoscale Physics · Physics 2016-03-07 Can Yesilyurt , Seng Ghee Tan , Gengchiau Liang , Mansoor B. A. Jalil

Monolayer graphene is an example of materials with multi-valley electronic structure. In such materials, the valley index is being considered as an information carrier. Consequently, relaxation mechanisms leading to loss of valley…

Mesoscale and Nanoscale Physics · Physics 2015-08-28 Péter Boross , András Pályi

We report on the emergence of bulk, valley-polarized currents in graphene-based devices, driven by spatially varying regions of broken sublattice symmetry, and revealed by non-local resistance ($R_\mathrm{NL}$) fingerprints. By using a…

Mesoscale and Nanoscale Physics · Physics 2021-03-10 Thomas Aktor , Jose H. Garcia , Stephan Roche , Antti-Pekka Jauho , Stephen R. Power

Half-metallicity (full spin polarization of the Fermi surface) usually occurs in strongly correlated electron systems. We demonstrate that doping a spin-density wave insulator in the weak-coupling regime may also stabilize half-metallic…

Strongly Correlated Electrons · Physics 2019-03-06 A. V. Rozhkov , A. L. Rakhmanov , A. O. Sboychakov , K. I. Kugel , F. Nori

We derive the angular generation density of photoexcited carriers in gapless and gapped Bernal bilayer graphene. Exploiting the strong anisotropy of the band structure of bilayer graphene at low energies due to trigonal warping, we show…

Mesoscale and Nanoscale Physics · Physics 2024-09-16 T. J. Osborne , M. E. Portnoi , E. Mariani

We describe an angularly asymmetric interface-scattering mechanism which allows to spatially separate the electrons in the two low-energy valleys of bilayer graphene. The effect occurs at electrostatically defined interfaces separating…

Mesoscale and Nanoscale Physics · Physics 2010-11-05 Henning Schomerus

In two-dimensional materials where interacting Fermi pockets occur in valleys related by time-reversal symmetry, a spontaneous valley imbalance results in a novel state known as an orbital magnet. Due to the breaking of time-reversal…

Mesoscale and Nanoscale Physics · Physics 2026-05-18 Fernando Peñaranda , Fernando de Juan

Flexoelectricity phenomenon is the response of electric polarization to an applied strain gradient and is developed as a consequence of crystal symmetry in all materials. In this study, we show that the presence of strain gradient in…

Computational Physics · Physics 2017-03-03 S. I. Kundalwal , S. A. Meguid , G. J. Weng

We demonstrate theoretically how local strains in graphene can be tailored to generate a valley polarized current. By suitable engineering of local strain profiles, we find that electrons in opposite valleys (K or K') show different…

Mesoscale and Nanoscale Physics · Physics 2013-05-29 Zhenhua Wu , F. Zhai , F. M. Peeters , H. Q. Xu , Kai Chang

We study graphene with an adsorbed spin texture, where the localized spins create a periodic magnetic flux. The latter produces gaps in the graphene spectrum and breaks the valley symmetry. The resulting effective electronic model, which is…

Materials Science · Physics 2011-03-31 Antonio Hill , Andreas Sinner , Klaus Ziegler

Ferromagnetism is most common in transition metal compounds but may also arise in low-density two-dimensional electron systems, with signatures observed in silicon, III-V semiconductor systems, and graphene moir\'e heterostructures. Here we…

The rise of graphene opens a new door to qubit implementation, as discussed in the recent proposal of valley pair qubits in double quantum dots of gapped graphene (Wu et al., arXiv: 1104.0443 [cond-mat.mes-hall]). The work here presents the…

Mesoscale and Nanoscale Physics · Physics 2011-07-05 G. Y. Wu , N. -Y. Lue , L. Chang

Half-metals have fully spin polarized charge carriers at the Fermi surface. Such polarization usually occurs due to strong electron--electron correlations. Recently [Phys. Rev. Lett. {\bf{119}}, 107601 (2017)], we have demonstrated…

Strongly Correlated Electrons · Physics 2018-11-13 A. L. Rakhmanov , A. O. Sboychakov , K. I. Kugel , A. V. Rozhkov , Franco Nori