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arXiv · 1007.2605

What is measured in the scanning gate microscopy of a quantum point contact?

Rodolfo A. Jalabert·Wojciech Szewc·Steven Tomsovic·Dietmar Weinmann
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Abstract

The conductance change due to a local perturbation in a phase-coherent nanostructure is calculated. The general expressions to first and second order in the perturbation are applied to the scanning gate microscopy of a two-dimensional electron gas containing a quantum point contact. The first-order correction depends on two scattering states with electrons incoming from opposite leads and is suppressed on a conductance plateau; it is significant in the step regions. On the plateaus, the dominant second-order term likewise depends on scattering states incoming from both sides. It is always negative, exhibits fringes, and has a spatial decay consistent with experiments.

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Rodolfo A. Jalabert, Wojciech Szewc, Steven Tomsovic, Dietmar Weinmann. 2010-10-12. What is measured in the scanning gate microscopy of a quantum point contact?. https://doi.org/10.1103/physrevlett.105.166802

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