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Seminar TPII/III EPVI


24.10.2017 4 p.m., room: S-288
Prof. Dr. Stefan Kirchner (Center for Correlated Matter, Zhejiang, University, Hangzhou, China)
Transport anomalies in ZrAs1.58Se0.39: Vacancies in the PbFCl structure as a route to two-channel Kondo physics
14.11.2017 4 p.m., room: S-288
Dr. Martin Hohenadler (Universität Würzburg)
Thema wird noch bekannt gegeben
28.11.2017 5 p.m., room: S-288
Prof. Dr. Björn Trauzettel (Universität Würzburg)
Chiral anomaly and fractional charges at the quantum spin Hall edge

The chiral anomaly is based on a non-conserved chiral charge and can happen in Dirac fermion systems under the influence of external electromagnetic fields. In this case, the spectral flow leads to a transfer of right- to left-moving excitations or vice versa. The corresponding transfer of chiral particles happens in momentum space. We here describe an intriguing way to introduce the chiral anomaly into real space. Our system consists of two quantum dots that are formed at the helical edges of a quantum spin Hall insulator by means of magnetic barriers. Such a setup gives rise to fractional charges which we show to be sharp quantum numbers for large barrier strength. Interestingly, it is possible to map the system onto a quantum spin Hall ring in the presence of a flux pierced through the ring where the relative angle between the magnetization directions of the barriers takes the role of the flux. The chiral anomaly in this system is then directly related to the excess occupation of particles in the two quantum dots. This analogy allows us to predict an observable consequence of the chiral anomaly in real space.

6.2.2018 4 p.m., room: S-288
Prof. Dr. Malte A. Peter (Institut für Mathematik, Angewandte Analysis, Universität Augsburg)
Localisation of classical waves in some disordered media