Helical edge resistance introduced by charge disorder

Electron puddles created by doping of a 2D topological insulator may violate the ideal helical edge conductance. Because of a long electron dwelling time, even a single puddle may lead to a significant inelastic backscattering. We find the resulting correction to the perfect edge conductance. Generalizing to multiple puddles, we assess the dependence of the helical edge resistance on temperature and on the doping level. Puddles with odd electron number carry a spin and lead to a logarithmically-weak temperature dependence of the resistivity of a long edge. The developed theory provides a framework for analyzing the results of the past and ongoing electron transport experiments with 2D topological insulators

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Mardi, Avril 29, 2014 - 15:30 to 17:00
Bob Room
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