Related papers: Optical valleytronics in gapped graphene
Nonreciprocity, which denotes the asymmetric or even unidirectional transmission of light, constitutes the cornerstone of modern photonic circuits. In the realm of photonic devices, it has been widely utilized in isolators, circulators and…
This work investigates the feasibility of electrical valley filtering for holes in transition metal dichalcogenides. We look specifically into the scheme that utilizes a potential barrier to produce valley-dependent tunneling rates, and…
We report on the possibility of valley number fractionalization in graphene with a topological defect that is accounted for in Dirac equation by a pseudomagnetic field. The valley number fractionalization is attributable to an imbalance on…
We propose a new design on integrated optical devices on-chip with an extra width degree of freedom by using a photonic crystal waveguide with Dirac points between two photonic crystals with opposite valley Chern numbers. With such an extra…
In a system with a Dirac-like linear dispersion there are always states that fulfill the resonance condition for electromagnetic radiation of arbitrary frequency $\Omega$. When a flat band is present two kinds of resonant transitions are…
The Corbino geometry allows one to investigate the propagation of electric current along a p-n interface in ballistic graphene in the absence of edge states appearing for the familiar Hall-bar geometry. Using the transfer matrix in the…
The valley degeneracy of electron states in graphene stimulates intensive research of valley-related optical and transport phenomena. While many proposals on how to manipulate valley states have been put forward, experimental access to the…
We theoretically study the effects of electron-electron interaction in twisted bilayer graphene in applied transverse dc electric field. When the twist angle is not very small, the electronic spectrum of the bilayer consists of four Dirac…
After having derived boundary conditions for dressed-state electrons in a dice lattice, we investigate the electron tunneling through a square electrostatic potential barrier in both dice lattices and graphene under a linearly-polarized…
Photon-assisted electron transport in ballistic graphene is analyzed using scattering theory. We show that the presence of an ac signal (applied to a gate electrode in a region of the system) has interesting consequences on electron…
We investigate the effect of an in-plane AC electric field coupled to electrons in the honeycomb lattice and show that it can be used to manipulate the Dirac points of the electronic structure. We find that the position of the Dirac points…
We study the effect of the strain on the band structure and the valley-dependent transport property of graphene heterojunctions. It is found that valley-dependent separation of electrons can be achieved by utilizing the strain and on-site…
Recent experiments have revealed that novel nonequilibrium states consistent with the hydrodynamic description of electrons are realized in ultrapure graphene, which hosts the valley degrees of freedom. Here, we formulate a theory of…
The conduction properties of a grain boundary junction with Fermi velocity mismatch are analyzed. We provide a generalization of the Dirac Hamiltonian model taking into account the Fermi velocity gradient at the interface. General boundary…
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…
Tunnelling of electrons in graphene-based junctions is studied theoretically. Graphene is assumed to be deposited either directly on a ferromagnetic insulator or on a few atomic layers of boron nitride which separate graphene from a…
Mesoscopic conductance fluctuations in graphene samples at energies not very close to the Dirac point are studied analytically. We demonstrate that the conductance variance $<[\delta G]^2>$ is very sensitive to the elastic scattering…
We introduce the concept of valley-layer coupling (VLC) in two-dimensional materials, where the low-energy electronic states in the emergent valleys have valley-contrasted layer polarization such that each state is spatially localized on…
Modifying the hexagonal lattices of graphene enables the repositioning and merging of the Dirac cones which proves to be a key element in the use of these materials for alternative electronic applications such as valleytronics. Here we…
The valley degree of freedom is one of the most intriguing properties of atomically thin transition metal dichalcogenides. Together with the possibility to address this degree of freedom by valley-contrasting optical selection rules, it has…