Related papers: Space charge and screening in bilayer graphene
We present a non-linear Thomas-Fermi theory which describes the electric charge screening in the system including two charged substrate layers separated by a few-layered graphene film. We show that by increasing the charge at the…
We demonstrate that for gapped bilayer graphene, the nonlinear nature of the screening of an external disorder potential and the resulting inhomogeneity of the electron liquid are crucial for describing the electronic compressibility. In…
Charge neutral bilayer graphene has a gapped ground state as transport experiments demonstrate. One of the plausible such ground states is layered antiferromagnetic spin density wave (LAF) state, where the spins in top and bottom layers…
The in-plane static screening of the field originated by a charge placed in a graphene sheet is investigated. A self-consistent field equation in the real space domain is obtained by using a suitable Thomas-Fermi procedure. Exact and…
This paper provides a variational treatment of the effect of external charges on the free charges in an infinite free-standing graphene sheet within the Thomas-Fermi theory. We establish existence, uniqueness and regularity of the energy…
Graphene is a two dimensional crystal of carbon atoms with fascinating electronic and morphological properties. The low energy excitations of the neutral, clean system are described by a massless Dirac Hamiltonian in (2+1) dimensions which…
Bilayer graphene -- two coupled single graphene layers stacked as in graphite -- provides the only known semiconductor with a gap that can be tuned externally through electric field effect. Here we use a tight binding approach to study how…
We have studied the dielectric screening of electric field which is induced by a gate voltage in twisted double bilayer graphene by using a sample with a mismatch angle of about 5 degrees. In low temperature magnetotransport measurements,…
We have theoretically studied the collective response properties of the two-dimensional chiral electron gas in bilayer graphene within the random phase approximation. The cooperation of external controlling factors like perpendicular…
We have investigated the Coulomb screening properties and collective excitations in a graphene bilayer. The static screening effect is anisotropic and is much stronger in the undoped graphene bilayer than in a monolayer graphene [1]. The…
We study charge fractionalization in bilayer graphene which is intimately related to its zero modes. In the unbiased case, the valley zero modes occur in pairs rendering it unsuitable for charge fractionalization. A bias plays the role of a…
Twisted double bilayer graphene is a compensated semi-metal near the charge neutrality point with the presence of small electron and hole pockets in its band structure. We show that strong Coulomb attraction between the electrons and holes…
Superfluidity has recently been reported in double electron-hole bilayer graphene. The multiband nature of the bilayers is important because of the very small band gaps between conduction and valence bands. The long range nature of the…
Electrons in two-dimensional graphene sheets behave as interacting chiral Dirac fermions and have unique screening properties due to their symmetry and reduced dimensionality. By using a combination of scanning tunneling spectroscopy…
We report room temperature scanning tunneling microscopy and spectroscopy study of bilayer graphene prepared by mechanical exfoliation on SiO$_2$/Si surface and electrically contacted with gold pads using a mechanical mask. The bulk…
A variety of two-dimensional materials possess a band structure with an energy extremal ridge along a ring in momentum space. Examples are biased bilayer graphene, and surfaces and interfaces with a Rashba spin-orbit interaction where at…
The discovery of electric field induced bandgap opening in bilayer graphene opens new door for making semiconducting graphene without aggressive size scaling or using expensive substrates. However, bilayer graphene samples have been limited…
Charge-neutral conducting systems represent a class of materials with unusual properties governed by electron-hole (e-h) interactions. Depending on the quasiparticles' statistics, band structure, and device geometry these semimetallic…
The charge susceptibility of twisted bilayer graphene is investigated in the Dirac cone, respectively random-phase approximation. For small enough twist angles $\theta\lesssim 2^\circ$ we find weakly Landau damped interband plasmons, i.~e.,…
The charge distribution induced by external fields in finite stacks of graphene planes, or in semiinfinite graphite is considered. The interlayer electronic hybridization is described by a nearest neighbor hopping term, and the charge…