Related papers: Optical valleytronics of impurity states in two-di…
Silicene (a monolayer of silicon atoms) is a topological insulator, which undergoes a topological phase transition to a band insulator under an external electric field. The spin polarization is unique and opposite at the K and K' points due…
The existence of large nonlinear optical coefficients is one of the preconditions for using nonlinear optical materials in nonlinear optical devices. For a crystal, such large coefficients can be achieved by matching photon energies with…
We describe here recent work on the electronic properties, magnetoexcitons and valley polarised electron gas in 2D crystals. Among 2D crystals, monolayer $MoS_2$ has attracted significant attention as a direct-gap 2D semiconductor analogue…
Within a two-band $k\cdot p$ method we analyze different types of strain for the $K$ valley optical characteristics of a freestanding monolayer MoS$_2$, MoSe$_2$, WS$_2$ and WSe$_2$. We predict that circular polarization selectivity for…
Diffusion currents are theoretically examined in two-dimensional Dirac materials, such as those of the transition metal dichalcogenides (TMD) family. The transversal effects are analogues of the valley Hall (VHE) and photogalvanic (PGE)…
We consider a two-dimensional crystalline monolayer of carbon atoms with a single non-magnetic impurity. Using the Weyl Hamiltonian to describe electronic energy spectrum near the Dirac points, we calculate the wave function and energy of…
Valleytronics rooted in the valley degree of freedom is of both theoretical and technological importance as it offers additional opportunities for information storage and electronic, magnetic and optical switches. In analogy to…
A uniaxial strain applied to graphene-like materials moves the Dirac nodes along the boundary of the Brillouin zone. An extreme case is the merging of the Dirac node positions to a single degenerate spectral node which gives rise to a new…
We present a unified theory of charge carrier transport in 2D Dirac systems with broken mirror inversion and time-reversal symmetries (e.g., as realized in ferromagnetic graphene). We find that the entanglement between spin and pseudospin…
We consider a bilayer geometry where a single impurity moves in a two-dimensional plane and is coupled, via dipolar interactions, to a two-dimensional system of fermions residing in the second layer. Dipoles in both layers point in the same…
We theoretically demonstrate that 100\% valley-polarized transport in monolayers of MoS$_{2}$ and other group-VI dichalcogenides can be obtained using off-resonant circularly polarized light. By tuning the intensity of the off-resonant…
Plasma photonic crystals designed in this paper are composed of gas discharge tubes to control the flow of electromagnetic waves. The band structures calculated by the finite element method are consistent with the experimental results in…
The valley degree of freedom of electrons in two-dimensional transition metal dichalcogenides has been extensively studied by theory, optical and optoelectronic experiments. However, generation and detection of pure valley current without…
Periodically driven systems can host many interesting and intriguing phenomena. The irradiated two-dimensional Dirac systems, driven by circularly polarized light, are the most attractive thanks to intuitive physical view of the absorption…
Topological insulators host Dirac surface states (SS) protected by time-reversal symmetry. Inter-surface hybridization can gap the SS and give rise to the quantum spin Hall effect in films that are sufficiently thin compared to the SS…
We review the theoretical and experimental results connected with the electron states in two-dimensional Dirac systems paying a special attention to the atomic collapse in graphene. Two-electron bound states of a Coulomb impurity are…
Long-range dipole-dipole interactions in subwavelength arrays of quantum emitters involve virtual photon exchange processes that impart forces on the emitters due to the imposed photon recoil. We perform a semi-classical analysis of the…
We investigate the optical conductivity, along with longitudinal and transverse conductivities, in buckled hexagonal lattice such as silicene subjected to both an in-plane magnetic field and a perpendicular electric field. In this model, we…
The exciting discovery of bi-dimensional systems in condensed matter physics has triggered the search of their photonic analogues. In this letter, we describe a general scheme to reproduce some of the systems ruled by a tight-binding…
The Lorentz-invariance-violating Weyl and Dirac fermions have recently attracted intensive interests as new types of particles beyond high-energy physics, and they demonstrate novel physical phenomena such as angle-dependent chiral anomaly…