Related papers: Floquet-Engineered Valleytronics in Dirac Systems
The electron's charge and spin degrees of freedom are at the core of modern electronic devices. With the in-depth investigation of two-dimensional materials, another degree of freedom, valley, has also attracted tremendous research…
Valleytronics using two-dimensional materials opens unprecedented opportunities for information processing with the valley polarizer being a basic building block. Paradigms such as strain engineering, the inclusion of line defects, and the…
We show that the optical excitation of graphene with polarized light leads to the pure valley current where carriers in the valleys counterflow. The current in each valley originates from asymmetry of optical transitions and electron…
This work investigates the Floquet dynamics of electrons and excitons (particle-hole pairs) in a Dirac material referred to as Kekul\'e-distorted graphene. Specifically, we examine the role played by a high frequency driving electromagnetic…
Low-energy excitations in graphene exhibit relativistic properties due to the linear dispersion relation close to the Dirac points in the first Brillouin zone. Two of the Dirac points located at opposite corners of the first Brillouin zone…
We analyze the quasienergy-spectrum and the valence to conduction-band transition probabilities of a tilted anisotropic Dirac material subject to linearly and circularly polarized electromagnetic fields. The quasienergy-spectrum is…
Intrinsic and extrinsic valley Hall effects are predicted to emerge in graphene systems with uniform or spatially-varying mass terms. Extrinsic mechanisms, mediated by the valley-dependent scattering of electrons at the Fermi surface, can…
The ability to optically engineer the Dirac band and electrically control the Fermi level in two-dimensional (2D) Dirac systems, such as graphene, has significantly advanced quantum technologies. However, similar tunability has remained…
We discuss the valley-orbit interaction (VOI) and the concept of VOI based valleytronics. Potential of such valleytronics is illustrated, with graphene as an example material, in several frontier applications comprising FETs, quantum…
The Floquet spectrum in an anisotropic tilted Dirac semimetal modulated by linearly polarized light is addressed through the solution of the time-dependent Schr\"odinger equation for the two-dimensional Dirac Hamiltonian via the Floquet…
Valleytronics has emerged as a promising paradigm, enabling comprehensive control of the valley degree of freedom (DoF) for energy-efficient and high-speed information processing. However, backscattering-induced valley depolarization…
We demonstrate how to control the spectra and current flow of Dirac electrons in both a graphene sheet and a topological insulator by applying either two linearly polarized laser fields with frequencies $\omega$ and $2\omega$ or a…
Modern light generation technology offers extraordinary capabilities for sculpting light pulses, with full control over individual electric field oscillations within each laser cycle. These capabilities are at the core of lightwave…
Valley polarization in graphene breaks inversion symmetry and therefore leads to second-harmonic generation. We present a complete theory of this effect within a single-particle approximation. It is shown that this may be a sensitive tool…
Achieving a population imbalance between the two inequivalent valleys is a critical first step for any valleytronic device. A valley-polarization can be induced in biased bilayer graphene using circularly polarized light. In this paper, we…
We consider a lateral hetero-junction where the left and right leads are made of monolayer graphene and the middle region is made of a gapped tilted Dirac material (borophene or quinoid graphene) illuminated with off-resonant circularly…
Valleytronics and valley photonics exploit the valley degree of freedom to encode and manipulate information. Here we show that photonic valleys can be selectively addressed in quantum optics using a simple two-level emitter, provided it is…
Propagation of an electron wave packet through a quantum point contact (QPC) defined by electrostatic gates in bilayer graphene is investigated. The gates provide a bias between the layers, in order to produce an energy gap. If the gates on…
Electromagnetic dressing by a high-frequency field drastically modifies the electronic transport properties on Dirac systems. Here its effects on the energy spectrum of graphene with two possible phases of Kekul\'e distortion (namely, Kek-Y…
Graphene provides a canonical setting for Floquet band engineering, where circularly polarized light can dynamically open topological gaps at Dirac points and generate nonequilibrium Hall responses. Here we show that uniaxial strain and…