Regensburg 2010 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 11: Transport

HL 11.7: Vortrag

Montag, 22. März 2010, 15:30–15:45, H14

Boltzmann equation approach to ballistic rectification at a potential step — •Daniel Urban and Jürgen König — Universität Duisburg-Essen and CeNIDE, Duisburg, Germany

We consider the device studied experimentally in Ref. [1]. It consists of a two-dimensional electron gas patterned such that two regions are separated by a potential step. Application of a bias voltage parallel to the potential step results in a transverse voltage (proportional to the square of the bias voltage). This effect can be exploited for rectification, since – due to the symmetry of the device – the transverse voltage does not depend on the bias polarity.

We model the electrons by means of the Boltzmann equation. In doing so we allow for non-parabolic dispersion and energy dependent scattering times. In order to capture the rectification effect, the distribution function has to be calculated to second order in the applied electric field. Based on the calculated distribution function we determine the transverse voltage. While its magnitude does not agree with the measured values in Ref. [1], qualitative features are reproduced: It depends quadratically on the applied bias and increases with increased mobility.

[1] A. Ganczarczyk et al., preprint: arXiv:0804.0689v3 (2009).