SearcharxivSearch

arXiv subjects

A. Hütten

Publications and source records attributed to A. Hütten.

2 recordsLinked to original sources

Landau levels, edge states, and strained magnetic waveguides in graphene monolayers with enhanced spin-orbit interaction

The electronic properties of a graphene monolayer in a magnetic and a strain-induced pseudo-magnetic field are studied in the presence of spin-orbit interactions (SOI) that are artificially enhanced, e.g., by suitable adatom deposition. For the homogeneous case, we provide analytical results for the Landau level eigenstates for arbitrary intrinsic and Rashba SOI, including also the Zeeman field. The edge states in a semi-infinite geometry are studied in the absence of the Rashba term. For a critical value of the magnetic field, we find a quantum phase transition separating two phases with spin-filtered helical edge states at the Dirac point. These phases have opposite spin current direction. We also discuss strained magnetic waveguides with inhomogeneous field profiles that allow for chiral snake orbits. Such waveguides are practically immune to disorder-induced backscattering, and the SOI provides non-trivial spin texture to these modes.

cond-mat.mes-hall

Magnetic scattering of Dirac fermions in topological insulators and graphene

We study quantum transport and scattering of massless Dirac fermions by spatially localized static magnetic fields. The employed model describes in a unified manner the effects of orbital magnetic fields, Zeeman and exchange fields in topological insulators, and the pseudo-magnetic fields caused by strain or defects in monolayer graphene. The general scattering theory is formulated, and for radially symmetric fields, the scattering amplitude and the total and transport cross sections are expressed in terms of phase shifts. As applications, we study ring-shaped magnetic fields (including the Aharanov-Bohm geometry) and scattering by magnetic dipoles.

cond-mat.mes-hall