Related papers: A controllable valley polarization in Graphene
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…
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,…
Valley, as a new degree of freedom for electrons, has drawn considerable attention due to its significant potential for encoding and storing information. Lifting the energy degeneracy to achieve valley polarization is necessary for…
Mechanical deformations in $\alpha$-$\mathcal{T}_3$ lattices induce local pseudomagnetic fields of opposite directionality for different valleys. When this strain is equipped with a dynamical drive, it generates a complementary…
Quantum states in graphene are four-fold degenerate: two fold in spins, and two fold in valleys.Both degrees of freedom can be utilized for qubit preparations. In our bilayer graphene quantumdots, we demonstrate that the valley g-factorgv,…
The selective control of specific momentum valleys lies at the core of valleytronics, a field that has thus far focused primarily on the $\mathbf{K}$ and $\mathbf{K'}$ valleys in transition metal dichalcogenides (TMDs). However, direct…
Dynamic wavelength tunability has long been the holy grail of photodetector technology. Because of its atomic thickness and unique properties, graphene opens up new paradigms to realize this concept, but so far this has been elusive…
Advances of condensed matter physics in exploiting the spin degree of freedom of electrons led to the emergence of the field of spintronics, which envisions new and more efficient approaches to data transfer, computing, and storage [1-3].…
We study the polarization dependence of optical absorption for the modified Haldane model, which exhibits antichiral edge modes in presence of sample boundaries and has been argued to be realizable in transition metal dichalcogenides or…
The ability to resolve the polarization of light with on-chip devices represents an urgent problem in optoelectronics. The detectors with polarization resolution demonstrated so far mostly require multiple oriented detectors or movable…
The theoretical results are presented showing that strain-induced anisotropy of graphene spectrum gives rise to the valley currents under the illumination by normally incident light. The currents of the two graphene valleys are mutually…
In analogy with light refraction at optical boundary, ballistic electrons also undergo refraction when propagate across a semiconductor junction. Establishing a negative refractive index in conventional optical materials is difficult, but…
Motivated by recent experiments in weakly hybridized small-angle twisted bilayer graphene, we investigate how valley imbalance affects the viscosity of two-dimensional Dirac fluids. We show that shifting the two low-energy Dirac cones…
Chirality is a fundamental property of electrons with the relativistic spectrum found in graphene and topological insulators. It plays a crucial role in relativistic phenomena, such as Klein tunneling, but it is difficult to visualize…
Producing currents predominantly from a single valley, namely valley-polarized currents, at optical-cycle timescales is an important aspect of the petahertz valleytronics, yet it remains less developed. This work exhibits the feasibility of…
The extreme mechanical resilience of graphene and the peculiar coupling it hosts between lattice and electronic degrees of freedom have spawned a strong impetus towards strain-engineered graphene where, on the one hand, strain augments the…
Strongly interacting two dimensional electron systems (2DESs) host a complex landscape of broken symmetry states. The possible ground states are further expanded by internal degrees of freedom such as spin or valley-isospin. While direct…
Tunneling transport across the p-n-p junction of Weyl semimetal with tilted energy dispersion is investigated. We report that the electrons around different valleys experience opposite direction refractions at the barrier interface when the…
We theoretically study valley-filtering in pristine graphene irradiated by bicircular counter-rotating laser drive. The dynamical symmetry of the graphene and laser drive disrupts graphene's inversion symmetry, which results distinct…
We study the quantum valley Hall effect and related domain wall modes in twisted bilayer graphene at a large commensurate angle. Due to the quantum valley and sub-valley Hall effect, a small deviation from the commensurate angle generates…