Related papers: Symmetry breaking and (pseudo)spin polarization in…
Graphene charge carriers behave as relativistic massless fermions, thereby exhibiting a variety of counter-intuitive behaviors. In particular, at p-n junctions, they behave as photons encountering a negative index media, therefore…
The feasibility of Veselago lensing in graphene with a p-n junction is investigated numerically for realistic injection leads. Two different set-ups with two narrow leads are considered with absorbing or reflecting side edges. This allows…
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…
The effect by which light focuses upon entering a medium with a negative refractive index, known as Veselago lensing, may enable optical imaging below the diffraction limit. Similarly, focusing electrons across a $pn$-junction could realize…
Massless Dirac fermions (MDFs) emerge as quasiparticles in various novel materials such as graphene and topological insulators, and they exhibit several intriguing properties, of which Veselago focusing is an outstanding example with a lot…
Negative refraction usually demands complex structure engineering while it is very natural for massless Dirac fermions (MDFs) across the \textit{p-n} junction, this leads to Dirac electron optics. The emergent Dirac materials may exhibit…
A remarkable property of intrinsic graphene is that upon doping, electrons and holes travel through the monolayer thick material with constant velocity which does not depend on energy up to about $0.3$ eV (Dirac fermions), as though the…
Ballistic heterojunctions of Dirac materials offer the opportunity of exploring optics-like phenomena in electronic systems. In this paper, a new perfect lens through special positive refraction is predicted with omnidirectional Klein…
The resolution of conventional optical lenses is limited by the wavelength. Materials with negative refractive index have been shown to enable the generation of an enhanced resolution image where both propagating and non-propagating waves…
We show that a graphene pnp junction with a central superconducting electrode acts as a Veselago lens for incoming electrons by focusing them and their phase-conjugated counterpart (holes) into different points of the optical axis. This…
Asymmetric Veselago lenses (AVLs) can be created from ballistic $p$-$n$ and $n$-$p$-$n$ homojunctions of uniaxially strained graphene. This atypical converging electron flow emerges by applying uniaxial tension out of the device's symmetry…
In this work, we study the spin polarization in the $MoS(Se)_{2}-WS(Se)_{2}$ Transition metal dichalcogenide heterostructures by using the non-equilibrium Green's function (NEGF) method and a three-band tight-binding model near the edges of…
The relativistic charge carriers in monolayer graphene can be manipulated in manners akin to conventional optics (electron-optics): angle-dependent Klein tunneling collimates an electron beam (analogous to a laser), while a Veselago…
We study theoretically the current-induced spin polarization effect in a two-terminal mesoscopic structure which is composed of a semiconductor two-dimensional electron gas (2DEG) bar with Rashba spin-orbit (SO) interaction and two attached…
We study the spin polarization of the electrons on the surface of topological insulators under a dc electric field or a circularly polarized light by using Keldysh Green's function formalism. When a dc electric field $E_x \sim 10^{3} {\rm…
Veselago pointed out that electromagnetic wave theory allows for materials with a negative index of refraction, in which most known optical phenomena would be reversed. A slab of such a material can focus light by negative refraction, an…
The current-voltage characteristics of a new range of devices built around Weyl semimetals has been predicted using the Landauer formalism. The potential step and barrier have been reconsidered for a three-dimensional Weyl semimetals, with…
Spin-dependent Kapitza-Dirac scattering of electron beams from counterpropagating bichromatic laser waves in various polarization geometries is studied. The corresponding scattering probabilities are obtained by analytical and numerical…
We theoretically study the spin and charge currents induced by a spin-motive force in a two-dimensional Dirac semimetal protected by nonsymmorphic symmetries. Glide mirror plane symmetry, a nonsymmorphic symmetry, leads to a constraint to…
Detection of the degree of circular polarization of the electroluminescence of a light-emitting diode fitted with a spin injecting contact (a spin-LED) allows for a direct determination of the spin polarization of the injected carriers.…