Regensburg 2013 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 30: Correlated Electrons: Quantum Impurities, Kondo Physics

TT 30.7: Talk

Tuesday, March 12, 2013, 11:15–11:30, H21

Single magnetic impurities in the Kane-Mele model — •Florian Goth, David J. Luitz, and Fakher F. Assaad — Institut für theoretische Physik und Astrophysik, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany

The realization of the spin-Hall effect in quantum wells has led to a plethora of studies regarding the properties of the edge states of a 2D topological insulator. These edge states constitute a class of one-dimensional liquids, called the helical liquid, where an electron’s spin direction is coupled to its direction of movement. In contrast to one dimensional conductors, magnetic impurities — below the Kondo temperature — cannot block transport and one expects the current to circumvent the impurity. To study this phenomenon, we consider the single impurity Anderson model embedded into an edge of a Kane-Mele ribbon with up to 512×80 sites and use numerically exact continuous time QMC methods to study the Kondo effect. We present results on the temperature dependence of the spectral properties of the impurity and the bulk system that show the behaviour of the system in the various regimes of the Anderson model. Furthermore we show results on the spatial behaviour of the spin-spin correlation functions.