22 citations · 26 across the 2 of their papers we have counts for
6 papers · 1 filter
Photoabsorption spectra and the X-ray edge problem in graphene
Georg Roeder, Grigory Tkachov, Martina Hentschel
We study the photoabsorption cross section and Fermi-edge singularities (FES) in graphene. For fillings below one half, we find, besides the expected FES in form of a peaked edge a…
Dirac fermion quantization on graphene edges: Isospin-orbit coupling, zero modes and spontaneous valley polarization
Grigory Tkachov
The paper addresses boundary electronic properties of graphene with a complex edge structure of the armchair/zigzag/armchair type. It is shown that the finite zigzag region support…
Boundary-induced violation of the Dirac fermion parity and its signatures in local and global tunneling spectra of graphene
Grigory Tkachov, Martina Hentschel
Extended defects in graphene, such as linear edges, break the translational invariance and can also have an impact on the symmetries specific to massless Dirac-like quasiparticles…
Spin-polarized tunneling through randomly transparent magnetic junctions: Reentrant magnetoresistance approaching the Julliere limit
Grigory Tkachov, Klaus Richter
Electron conductance in planar magnetic tunnel junctions with long-range barrier disorder is studied within Glauber-eikonal approximation enabling exact disorder ensemble averaging…
Fine structure of the local pseudogap and Fano effect for superconducting electrons near a zigzag graphene edge
Grigory Tkachov
Motivated by recent scanning tunneling experiments on zigzag-terminated graphene this paper investigates an interplay of evanescent and extended quasiparticle states in the local d…
Geometrical enhancement of the proximity effect in quantum wires with extended superconducting tunnel contacts
Giorgos Fagas, Grigory Tkachov, Andreas Pfund +1
We study Andreev reflection in a ballistic one-dimensional channel coupled in parallel to a superconductor via a tunnel barrier of finite length . The dependence of the low-ener…