Dresden 2009 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 17: Quantum wires: Optical and transport properties

HL 17.6: Vortrag

Dienstag, 24. März 2009, 11:30–11:45, BEY 154

Evanescent channels and scattering in cylindrical nanowire heterostructures — •Paul Nicolae Racec^1,2, Elena Roxana Racec^3,4, and Hagen Neidhardt¹ — ¹Weierstraß-Institut für Angewandte Analysis und Stochastik, Mohrenstr. 39 10117 Berlin, Germany — ²National Institute of Materials Physics, PO Box MG-7,077125 Bucharest Magurele, Romania — ³Institut für Physik, Technische Universität Cottbus, Postfach 101344, 03013 Cottbus, Germany — ⁴Faculty of Physics, University of Bucharest, PO Box MG-11,077125 Bucharest Magurele, Romania

We investigate the scattering phenomena produced by a general finite range non-separable potential in a multi-channel two-probe cylindrical nanowire heterostructure. The multi-channel current scattering matrix is efficiently computed using the R-matrix formalism extended for cylindrical coordinates. Considering the contribution of the evanescent channels to the scattering matrix, we were able to put in evidence the specific dips in the tunneling probability in the case of an attractive scattering potential. The cylindrical symmetry cancels the "selection rules" known for Cartesian coordinates. Detailed maps of the localization probability density sustain the physical interpretation of the resonances. We present numerical results for a quantum dot embedded into the nano-cylinder and a double barrier along the nano-cylinder.