Regensburg 2010 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 48: Semiconductor Lasers

HL 48.12: Vortrag

Donnerstag, 25. März 2010, 12:30–12:45, H13

Efficient modeling of non-equilibrium quantum transport in 3D nanostructures — •Peter Greck, Christoph Schindler, and Peter Vogl — Technische Universität München, Germany

We present non-equilibrium Green's function (NEGF) alculations based on an extension of the standard Büttiker Probe model [1]. Büttiker Probes provide a phenomenological method to model incoherent scattering very efficiently. However, any effects of discrete energy coupling (e.g. by optical phonons) are not captured due to the simple structure of the model. Therefore, devices relying on resonant phonon effects such as THz quantum cascade lasers (QCLs) call for more sophisticated models for the scattering self energies. While the self-consistent Born approximation provides the required accuracy, it is extremely costly in terms of computational resources, especially for 3D nanostructures. We have extended the standard Büttiker Probe model in a way that accurately accounts for optical phonon scattering without losing the computational efficiency and simplicity of the Büttiker Probe model. The method allows one to control the scattering mechanisms individually. This renders realistic quantum transport calculations of 3D nanostructures feasible. We present detailed calculations of mid-infrared quantum cascade structures and compare the results with experimental data as well as with full NEGF results [2]. [1] M. Büttiker, Phys. Rev. Lett. 57, 1761 (1986) [2] T. Kubis, C. Yeh, P. Vogl, A. Benz, G. Fasching, and C. Deutsch, Phys. Rev. B 79, 195323 (2009)