Regensburg 2002 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 11: Poster 1

HL 11.70: Poster

Montag, 11. März 2002, 17:00–19:30, Poster A

Landau band structure of magnetic lateral 1d superlattices — •Christian Lechner, Michael Langenbuch, Roland Onderka, Michael Suhrke, and Ulrich Rössler — Institut für Theoretische Physik, Universität Regensburg, 93040 Regensburg, Germany

The degeneracy of Landau levels in the two-dimensional electron system (2DES) is due to its homogeneity or invariance against arbitrary lateral translations. We remove this invariance by considering an inhomogeneous magnetic field perpendicular to the plane of the 2DES in form of a periodic modulation in one direction. As a consequence the degeneracy of the Landau levels is removed and magnetic minibands (or Landau bands) are formed as for the case of electrostatic lateral periodic potentials. We solve this quantum mechanical problem and study its consequences for the low-field magnetoconductivity by evaluating the Kubo formula. We interpret features of the miniband stucture by using the classical pictures of channeling orbits by comparing energies and analyzing wave functions. For comparison with experiments, which cannot be realized with a purely magnetic modulation, we consider the mixed case of electrostatic and magnetic modulation.