Related papers: Gate-tunable Topological Valley Transport in Bilay…
We report the discovery of electric-field-induced transition from a topologically trivial to a topologically nontrivial band structure in an atomically sharp heterostructure of bilayer graphene (BLG) and single-layer WSe2 per the…
The development of valleytronics demands long-range electronic transport with preserved valley index, a degree of freedom similar to electron spin. A promising structure for this end is a topological one-dimensional (1D) channel formed in…
Realizations of some topological phases in two-dimensional systems rely on the challenge of jointly incorporating spin-orbit and magnetic exchange interactions. Here, we predict the formation and control of a fully valley-polarized quantum…
Valley pseudospin, labeling quantum states of energy extrema in momentum space, is attracting tremendous attention1-13 because of its potential in constructing new carrier of information. Compared with the non-topological bulk valley…
The existence of inequivalent valleys K and K' in the momentum space of two-dimensional hexagonal lattices provides a new electronic degree of freedom, the manipulation of which can potentially lead to new types of electronics, in analogy…
Interlayer sliding, together with twist angle, is a crucial parameter that defines the atomic registry and thus determines the properties of two-dimensional (2D) material homobilayers. Here, we theoretically demonstrate that controlled…
The effective theory for bilayer graphene (BLG), subject to parallel/in-plane magnetic fields, is derived. With a sizable magnetic field the trigonal warping becomes irrelevant, and one ends up with two Dirac points in the vicinity of each…
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…
2D materials based superlattices have emerged as a promising platform to modulate band structure and its symmetries. In particular, moir\'e periodicity in twisted graphene systems produces flat Chern bands. The recent observation of…
Using the B\"{u}ttiker-Landauer formulation of transport theory in the linear response regime, the valley currents and non-local resistances of bilayer graphene nanostructures with broken inversion symmetry are calculated. It is shown that…
Twisted bilayer graphene gives rise to large moir\'{e} patterns that form a triangular network upon mechanical relaxation. If gating is included, each triangular region has gapped electronic Dirac points that behave as bulk topological…
We theoretically investigate gate-defined graphene superlattices with broken inversion symmetry as a platform for realizing tunable valley dependent transport. Our analysis is motivated by recent experiments [C. Forsythe et al., Nat.…
The intrinsic valley degree of freedom makes bilayer graphene (BLG) a unique platform for semiconductor qubits. The single-carrier quantum dot (QD) ground state exhibits a two-fold degeneracy, where the two states that constitute a Kramers…
Bilayer graphene (BLG)-based quantum devices represent a promising platform for emerging technologies, such as quantum computing and spintronics. However, their intrinsically weak spin-orbit coupling (SOC) complicates spin and valley…
It is shown that potential barriers in bilayer graphene (BLG) and monolayer transition metal dichalcogenides (TMDs) can split a valley unpolarized incident current into reflected and transmitted currents with opposite valley polarization.…
Emergent phenomena arising from the collective behavior of electrons is generally expected when Coulomb interactions dominate over the kinetic energy, as in delocalized quasiparticles in highly degenerate flat bands. Bernal-stacked bilayer…
Twisted double bilayer graphene (tDBG) comprises two Bernal-stacked bilayer graphene sheets with a twist between them. Gate voltages applied to top and back gates of a tDBG device tune both the flatness and topology of the electronic bands,…
Our theoretical study unfolds the topological phase transitions (within bands of the Moir\'e super-lattice) in small angle twisted double bilayer graphene (tDBLG) under the influence of external gate voltage and intrinsic spin-orbit…
Superlattices (SLs) in monolayer and bilayer graphene, formed by spatially periodic potential variations, lead to a modified bandstructure with extra finite-energy and zero-energy Dirac fermions with tunable anisotropic velocities. We…
In bilayer graphene, electrostatic confinement can be realized by a suitable design of top and back gate electrodes. We measure electronic transport through a bilayer graphene quantum dot, which is laterally confined by gapped regions and…