Unusual Hyperfine Interaction of Dirac Electrons and NMR Spectroscopy in Graphene

Unusual hyperfine interaction of dirac electrons and NMR spectroscopy in graphene.

A theory of nuclear magnetic resonance (NMR) in graphene is presented. The canonical form of the electron-nucleus hyperfine interaction is strongly modified by the linear electronic dispersion. The NMR shift and spin-lattice relaxation time are calculated as a function of temperature, chemical potential, and magnetic field, and three distinct regimes are identified: Fermi-, Dirac-gas, and extre...

Collective Excitations of Dirac Electrons in Graphene

Two-dimensional electrons in graphene are known to behave as massless fermions with Dirac-Weyl type linear dispersion near the Dirac crossing points. We have investigated the collective excitations of this system in the presence or absence of an external magnetic field. Unlike in the conventional two-dimensional electron system, the ν = 1 m fractional quantum Hall state in graphene was found to...

Localization of dirac electrons in rotated graphene bilayers.

For Dirac electrons the Klein paradox implies that the confinement is difficult to achieve with an electrostatic potential although it can be of great importance for graphene-based devices. Here, ab initio and tight-binding approaches are combined and show that the wave function of Dirac electrons can be localized in rotated graphene bilayers due to the Moire pattern. This localization of wave ...

Comment on "BCS superconductivity of dirac electrons in graphene layers".

Possible superconductivity of electrons with the Dirac spectrum is analyzed using the BCS model. We calculate the critical temperature, the superconducting energy gap, and the supercurrent as functions of the doping level and of the pairing interaction strength. Zero doping is characterized by the existence of a quantum critical point such that the critical temperature vanishes below some finit...

Orbital selective coupling between Ni adatoms and graphene Dirac electrons