English
Related papers

Related papers: Valley polarization induced second harmonic genera…

200 papers

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…

Mesoscale and Nanoscale Physics · Physics 2022-05-05 Ryotaro Sano , Daigo Oue , Mamoru Matsuo

Optical second harmonic generation (SHG) is studied from multilayer graphene films in the presence of DC electric current flowing in the sample plane. Graphene layers are manufactured by chemical vapour deposition (CVD) technique and…

Mesoscale and Nanoscale Physics · Physics 2015-06-04 Anton Y. Bykov , Tatiana V. Murzina , Maxim G. Rybin , Elena D. Obraztsova

We recently shown, using tight-binding calculations, that nonequilibrium valley polarization can be realized in graphene, when the current is injected through "valley filter": a ballistic point contact with zigzag edges. Here we…

Mesoscale and Nanoscale Physics · Physics 2008-05-23 Adam Rycerz

The dynamic polarization for kekul\'e-patterned graphene is studied within the Random Phase Approximation (RPA). It is shown how the breaking of the valley degeneracy by the lattice modulation is manifested through the dielectric spectrum,…

Mesoscale and Nanoscale Physics · Physics 2020-12-03 Saúl A. Herrera , Gerardo G. Naumis

Degenerate minima in momentum space - valleys - provide an additional degree of freedom that can be used for information transport and storage. Notably, such minima naturally exist in the band structure of transition metal dichalcogenides…

We consider coherent dynamics of graphene charged carriers exposed to an intense few-cycle linearly polarized laser pulse. The results, obtained by solving the generalized semiconductor Bloch equations numerically in the Hartree-Fock…

Analogous to charge and spin, electrons in solids endows an additional degree of freedom: the valley pseudospin. Two-dimensional hexagonal materials such as graphene exhibit two valleys, labelled as $\mathbf{K}$ and $\mathbf{K}^{\prime}$.…

Mesoscale and Nanoscale Physics · Physics 2022-01-12 M. S. Mrudul , Gopal Dixit

This work performs a numerical study of electron transport through the fundamental logic gate in valleytronics - a valley valve consisting of two or increasing number of valley filters. Various typical effects on the transport are…

Mesoscale and Nanoscale Physics · Physics 2022-11-09 Jia-Huei Jiang , Ning-Yuan Lue , Feng-Wu Chen , Yu-Shu G. Wu

We propose a device for the generation of valley polarized electronic current in bilayer graphene. By analyzing the response of this material to intense terahertz frequency light in the presence of a transverse electric field, we…

Mesoscale and Nanoscale Physics · Physics 2009-08-20 D. S. L. Abergel , Tapash Chakraborty

We theoretically investigate the second harmonic generation and photon drag effect induced by an incident plane wave to a doped graphene placed on a two-dimensional diffraction grating. The relevant nonlinear conductivity of the graphene is…

Optics · Physics 2018-10-04 Tetsuyuki Ochiai

Valley filtering processes have been explored in different graphene-based configurations and scenarios to control transport responses. Here we propose graphene multi-terminal set-ups properly designed to obtain valley filtered currents in a…

Mesoscale and Nanoscale Physics · Physics 2021-03-31 Vanessa Torres , Daiara Faria , Andrea Latgé

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…

Mesoscale and Nanoscale Physics · Physics 2021-07-07 Fionnuala Solomon , Stephen R. Power

Nonlinear second harmonic optical activity of graphene covering a gold photon sieve was determined for different polarizations. The photon sieve consists of a subwavelength gold nanohole array placed on glass. It combines the benefits of…

Mesoscale and Nanoscale Physics · Physics 2016-01-14 Michael Lobet , Michael Sarrazin , Francesca Cecchet , Nicolas Reckinger , Alexandru Vlad , Jean-François Colomer , Dan Lis

Valley filters are crucial to any device exploiting the valley degree of freedom. By using an atomistic model, we analyze the mechanism leading to the valley filtering produced by a line-defect in graphene and show how it can be inverted by…

Mesoscale and Nanoscale Physics · Physics 2016-10-11 Lucas H. Ingaramo , Luis E. F. Foa Torres

An analytical theory of the nonlinear electromagnetic response of a two-dimensional (2D) electron system in the second order in the electric field amplitude is developed. The second-order polarizability and the intensity of the second…

Mesoscale and Nanoscale Physics · Physics 2015-05-27 S. A. Mikhailov

The illumination of a single-layer transition metal dichalcogenide with an elliptically-polarized light beam is shown to give rise to a differential rate of inter-band carrier excitation between the valence and conduction states around the…

Materials Science · Physics 2017-03-28 Parijat Sengupta , Yaohua Tan , Dmitris Pavlidis , Junxia Shi

We investigate the electronic dispersion and transport properties of graphene/WSe$_{2}$ heterostructures in the presence of a proximity-induced spin-orbit coupling $\lambda_{v}$, sublattice potential $\Delta$, and an off-resonant circularly…

Mesoscale and Nanoscale Physics · Physics 2023-07-07 M. Zubair , P. Vasilopoulos , M. Tahir

Graphene, and other members of the monolayer Xene family, represent an ideal materials platform for "valleytronics", the control of valley localized charge excitations. The absence of a gap in these semi-metals, however, precludes valley…

Monolayer graphene is an example of materials with multi-valley electronic structure. In such materials, the valley index is being considered as an information carrier. Consequently, relaxation mechanisms leading to loss of valley…

Mesoscale and Nanoscale Physics · Physics 2015-08-28 Péter Boross , András Pályi

We investigate physical properties that can be used to distinguish the valley degree of freedom in systems where inversion symmetry is broken, using graphene systems as examples. We show that the pseudospin associated with the valley index…

Materials Science · Physics 2011-11-10 Di Xiao , Wang Yao , Qian Niu