Related papers: Klein tunnelling and Hartman effect in graphene ju…
Graphene has demonstrated great promise for future electronics technology as well as fundamental physics applications because of its linear energy-momentum dispersion relations which cross at the Dirac point. However, accessing the physics…
We study the interplay of Klein tunneling (= interband tunneling) between n-doped and p-doped regions in graphene and Andreev reflection (= electron-hole conversion) at a superconducting electrode. The tunneling conductance of an n-p-n…
Hexagonal boron-nitride (h-BN) provides an ideal substrate for supporting graphene devices to achieve fascinating transport properties, such as Klein tunneling, electron optics and other novel quantum transport phenomena. However,…
Spatially varying strained graphene can acquire interesting electronic properties because of the strain-induced valley-dependent gauge (pseudomagnetic) fields1,2. Here we report the realization of strained graphene regions located close to…
We analyze the problem of electronic transmission through different regions of a graphene sheet that are characterized by different types of connections between the Dirac points. These valley symmetry breaking Hamiltonians might arise from…
When electrons are confined in two dimensions and subjected to strong magnetic fields, the Coulomb interactions between them become dominant and can lead to novel states of matter such as fractional quantum Hall liquids. In these liquids…
We investigate the emergence of extra Dirac points in the electronic structure of a periodically spaced barrier system, i.e., a superlattice, on single-layer graphene, using a Dirac-type Hamiltonian. Using square barriers allows us to find…
It is highly desirable to integrate graphene into existing semiconductor technology, where the combined system is thermodynamically stable yet maintain a Dirac cone at the Fermi level. Firstprinciples calculations reveal that a certain…
Due to the weak spin-orbit interaction and the peculiar relativistic dispersion in graphene, there are exciting proposals to build spin qubits in graphene nanoribbons with armchair boundaries. However, the mutual interactions between…
Recent experiments on the role of electron-electron interactions in fractal Dirac systems have revealed a host of interesting effects, in particular, the unique nature of the magnetic field dependence of butterfly gaps in graphene. The…
The electronic density of states of graphene is equivalent to that of relativistic electrons. In the absence of disorder or external doping the Fermi energy lies at the Dirac point where the density of states vanishes. Although transport…
We investigate the twist-angle and gate dependence of the proximity exchange coupling in twisted graphene on monolayer Cr$_2$Ge$_2$Te$_6$ from first principles. The proximitized Dirac band dispersions of graphene are fitted to a model…
We study the low-energy electronic transport across periodic extended defects in graphene. In the continuum low-energy limit, such defects act as infinitesimally thin stripes separating two regions where Dirac Hamiltonian governs the…
The proximity-induced couplings in graphene due to the vicinity of a ferromagnetic insulator are analyzed. We combine general symmetry principles and simple tight-binding descriptions to consider different orientations of the magnetization.…
Graphene on an insulating ferromagnetic substrate---ferromagnetic insulator or ferromagnetic metal with a tunnel barrier---is expected to exhibit giant proximity exchange and spin-orbit couplings. We use a realistic transport model of…
We show that Andreev reflection in a junction between ferromagnetic (F) and superconducting (S) graphene regions is fundamentally different from the common FS junctions. For a weakly doped F graphene with an exchange field $h$ larger than…
We study the electronic states of graphene in piecewise constant potentials using the continuum Dirac equation appropriate at low energies, and a transfer matrix method. For superlattice potentials, we identify patterns of induced Dirac…
The chemical stability of graphene and other free-standing two-dimensional crystals means that they can be stacked in different combinations to produce a new class of functional materials, designed for specific device applications. Here we…
The different physical properties of multilayered graphene or graphite relative to single layer graphene result from the Dirac spins symmetry in graphene and the Pauli spin symmetry in graphite. The Dirac symmetry in multilayers of graphene…
We articulate the challenges and opportunities of unconventional devices using the photon like flow of electrons in graphene, such as Graphene Klein Tunnel (GKT) transistors. The underlying physics is the employment of momentum rather than…