WIAS Preprint No. 1452, (2009)

R-matrix formalism for electron scattering in two dimensions



Authors

  • Racec, Paul N.
  • Racec, Roxana
  • Neidhardt, Hagen

2010 Mathematics Subject Classification

  • 35Q40 35P25 35B34

2008 Physics and Astronomy Classification Scheme

  • 72.20.Dp, 73.40.-c, 73.63.-b

Keywords

  • scattering, quantum transport, resonances, quantum dot, nanowire

Abstract

We investigate the scattering phenomena in two dimensions produced by a general finite-range nonseparable potential. This situation can appear either in a Cartesian geometry or in a heterostructure with cylindrical symmetry. Increasing the dimensionality of the scattering problem new processes as the scattering between conducting channels and the scattering from conducting to evanescent channels are allowed. For certain values of the energy, called resonance energy, the transmission through the scattering region changes dramatically in comparison with an one-dimensional problem. If the potential has an attractive character even the evanescent channels can be seen as dips of the total transmission. The multi-channel current scattering matrix is determined using its representation in terms of the R-matrix. The resonant transmission peaks are characterized quantitatively through the poles of the current scattering matrix. Detailed maps of the localization probability density sustain the physical interpretation of the resonances. Our formalism is applied to a quantum dot in a two dimensional electron gas and a conical quantum dot embedded inside a nanowire.

Appeared in

  • Trends in Nanophysics, A. Aldea, V. Bârsan, eds., Engineering Materials, Springer, Berlin/Heidelberg, 2010, pp. 149--174

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