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In this paper we develop the theory for 2D-to-2D tunneling spectroscopy aided by magnetic or quantum-order excitations, and apply it to the description of van-der-Waals heterostructures of graphene/ultrathin $\alpha-{\rm RuCl}_3$. We study…

Mesoscale and Nanoscale Physics · Physics 2025-07-14 Matteo Carrega , Ivan J. Vera-Marun , Alessandro Principi

Electrons in graphene are described by relativistic Dirac-Weyl spinors with a two-component pseudospin1-12. The unique pseudospin structure of Dirac electrons leads to emerging phenomena such as the massless Dirac cone2, anomalous quantum…

We show that the valley Chern number of the low energy band in twisted double bilayer graphene can be tuned through two successive topological transitions, where the direct bandgap closes, by changing the electric field perpendicular to the…

Mesoscale and Nanoscale Physics · Physics 2021-05-05 Priyanka Mohan , Unmesh Ghorai , Rajdeep Sensarma

The relativistic-like behavior of electrons in graphene significantly influences the interaction properties of these electrons in a quantizing magnetic field, resulting in more stable fractional quantum Hall effect states as compared to…

Mesoscale and Nanoscale Physics · Physics 2015-06-15 Tapash Chakraborty , Vadim Apalkov

Klein tunneling refers to the absence of normal backscattering of electrons even under the case of high potential barriers. At the barrier interface, the perfect matching of electron and hole wavefunctions enables a unit transmission…

Mesoscale and Nanoscale Physics · Physics 2016-12-20 Can Yesilyurt , Seng Ghee Tan , Gengchiau Liang , Mansoor B. A. Jalil

We show that the chiral modes in circular graphene $pn$ junctions provide an advantage for spin manipulation via spin-orbit coupling compared to semiconductor platforms. We derive the effective Hamiltonian for the spin dynamics of the…

Mesoscale and Nanoscale Physics · Physics 2023-09-28 Dario Bercioux , Diego Frustaglia , Alessandro De Martino

Chirality is a fundamental feature in all domains of nature, ranging from particle physics over electromagnetism to chemistry and biology. Chiral objects lack a mirror plane and inversion symmetry and therefore cannot be spatially aligned…

We investigate a valleytronic device based on graphene with charge separation at different sublattices and correspondingly at nonequivalent valleys. We characterize the maximality condition of valley polarization and investigate the…

Mesoscale and Nanoscale Physics · Physics 2021-01-08 Hamed Koochaki Kelardeh , Mohammadreza Eidi , Takashi Oka , Jan Michael Rost

We study the effect of trigonal warping on the focussing of electrons by n-p junctions in graphene. We find that perfect focussing, which was predicted for massless Dirac fermions, is only preserved for one specific sample orientation. In…

Mesoscale and Nanoscale Physics · Physics 2017-07-25 K. J. A. Reijnders , M. I. Katsnelson

We analyze spin scattering in ballistic transport of electrons through a ripple at a normal incidence of an electron flow. The model of a ripple consists of a curved graphene surface in the form of an arc of a circle connected from the…

Mesoscale and Nanoscale Physics · Physics 2015-12-08 M. Pudlak , K. N. Pichugin , R. G. Nazmitdinov

The relativistic nature of charge carriers in graphene is expected to lead to an angle- dependent transmission through a potential barrier, where Klein tunneling involves annihilation of an electron and a hole at the edges of the barrier.…

Mesoscale and Nanoscale Physics · Physics 2014-01-29 Atikur Rahman , Janice Wynn Guikema , N. M. Hassan , Nina Markovic

Generating discernible valley contrasts and segregating valley-indexed fermions in real space within graphene poses considerable challenges due to the isotropic transport within the continuum energy range for degenerate valleys. This study…

Mesoscale and Nanoscale Physics · Physics 2024-02-23 Shrushti Tapar , Bhaskaran Muralidharan

Controlling the polarization state of electromagnetic radiation enables the investigation of fundamental symmetry properties of matter through chiroptical processes. Many strategies have been developed to reveal structural or dynamical…

In this paper, a simple method is proposed to get analytical solutions (or with the help of a finite numerical calculations) of the Dirac-Weyl equation for low energy electrons in graphene in the presence of certain electric and magnetic…

Mathematical Physics · Physics 2022-12-20 İsmail Burak Ateş , Şengül Kuru , Javier Negro

The paper addresses boundary electronic properties of graphene with a complex edge structure of the armchair/zigzag/armchair type. It is shown that the finite zigzag region supports edge bound states with discrete equidistant spectrum…

Mesoscale and Nanoscale Physics · Physics 2009-02-02 Grigory Tkachov

The origin and function of chirality in DNA, proteins, and other building blocks of life represent a central question in biology. Observations of spin polarization and magnetization associated with electron transport through chiral…

Dirac electrons in graphene are to lowest order spin 1/2 particles, owing to the orbital symmetries at the Fermi level. However, anisotropic corrections in the $g$-factor appear due to the intricate spin-valley-orbit coupling of chiral…

Mesoscale and Nanoscale Physics · Physics 2021-08-11 Marta Prada , Lars Tiemann , Jonas Sichau , Robert H Blick

Polar textures have attracted significant attention in recent years as a promising analog to spin-based textures in ferromagnets. Here, using optical second harmonic generation based circular dichroism, we demonstrate deterministic and…

Precise probe and control of various quantum degrees of freedom in novel quantum matter are central to understanding fundamental quantum physics and hold promise for innovative routes to encode and process information. Chirality is one such…

Electron chirality has been proposed as a microscopic quantity that characterizes electronic handedness, yet its underlying control parameter has not been clearly identified. Furthermore, its applicability is limited to systems with…