Related papers: Ultrafast valley polarization in bilayer graphene
A nanoelectronic device made of twisted bilayer graphene (TBLG) is proposed to steer the direction of the current flow. The ballistic electron current, injected at one edge of the bottom layer, can be guided predominantly to one of the…
Focusing on the twist angle for the minimal commensurate structure, we perform nonperturbative calculations of electron dynamics in the twisted bilayer graphene (TBG) under intense laser fields. We show that the TBG exhibits enriched…
We theoretically investigate the effect of broken inversion symmetry on the generation and control of ultrafast currents in a transparent dielectric (SiO2) by strong femto-second optical laser pulses. Ab-initio simulations based on…
We develop a general theory of the layer circular photogalvanic effect (LCPGE) in quasi two-dimensional chiral bilayers, which refers to the appearance of a polarization-dependent, out-of-plane dipole moment induced by circularly polarized…
The radio polarization properties of the pulsar population are only superficially captured by the conventional picture of pulsar radio emission. We study the broadband polarization of 271 young radio pulsars, focusing particularly on…
Symmetries associated with the Hamiltonian describing bilayer graphene subjected to a constant magnetic field perpendicular to the plane of the bilayer are calculated using polar coordinates. These symmetries are then applied to explain…
In transition metal dichalcogenides, the valley degree of freedom directly couples valley-polarised excitons - excited by circularly polarised light - to valley-dependent chiral photons, enabling ultrafast light-driven valleytronics.…
We propose a simple, yet highly efficient and robust device for producing valley polarized current in graphene. The device comprises of two distinct components; a region of uniform uniaxial strain, adjacent to an out-of-plane magnetic…
Here we proposed the valley selective excitations via a two-color (\ensuremath{\omega} + \ensuremath{2\omega}) laser field, made by superimposing two linearly polarized pulses at frequencies \ensuremath{\omega} and \ensuremath{2\omega}. We…
At the 2D limit, hexagonal systems such as monolayer transition metal dichalcogenides (TMDs) and graphene exhibit unique coupled spin and momentum-valley physics (valley pseudospin) owing to broken spatial inversion symmetry and strong…
Valley degrees of freedom offer a potential resource for quantum information processing if they can be effectively controlled. We discuss an optical approach to this problem in which intense light breaks electronic symmetries of a…
We calculate the plasmon frequency and damping rate of plasma oscillations in a spin-polarized BLG system. Using the long wavelength approximation for dynamical dielectric function, we obtain an analytical expression for plasmon frequency…
We study transport in twisted bilayer graphene and show that electrostatic barriers can act as valley splitters, where electrons from the $K$ ($K'$) valley are transmitted only to e.g.\ the top (bottom) layer, leading to valley-layer locked…
Selective control over the emission pattern of valley-polarized excitons in monolayer transition metal dichalcogenides is crucial for developing novel valleytronic, quantum information, and optoelectronic devices. While significant progress…
We show theoretically and demonstrate experimentally that collapsing elliptically-polarized laser beams experience a nonlinear ellipse rotation that is highly sensitive to small fluctuations in the input power. For arbitrarily small…
Using scanning probe microscopy and spectroscopy, we explore the spatial symmetry of the electronic wavefunctions of twisted bilayer graphene at the "magic angle" of 1.1 degrees. This small twist angle leads to a long wavelength moir\'e…
Electrons in two-dimensional materials possess an additional quantum attribute, the valley pseudospin, labelled as $\mathbf{K}$ and $\mathbf{K}^{\prime}$ -- analogous to the spin up and spin down. The majority of research to achieve…
Memory or transistor devices based on electron's spin rather than its charge degree of freedom offer certain distinct advantages and comprise a cornerstone of spintronics. Recent years have witnessed the emergence of a new field,…
Unidirectional control of optically induced spin waves in a rare-earth iron garnet crystal is demonstrated. We observed the interference of two spin-wave packets with different initial phases generated by circularly polarized light pulses.…
We describe a broadband optical device that is capable of rotating the polarization plane of a linearly polarized light at any desired angle over a wide range of wavelengths. The device is composed of a sequence of half-wave plates rotated…