Sonderseminare TRR80

25.10.2017 16:00, Raum: R-242
Dr. Peter Milde (TU Dresden, Institute of Applied Physics, Dresden)
Scanning Force Microscopy Investigations of Skyrmions
26.10.2017 14:00, Raum: S-254
Prof. Dr. Vasily Moshnyaga (Georg-August-Universität Göttingen, Germany)
Order / disorder phenomena in perovskite films
14.11.2017 16:00, Raum: S-288
Dr. Martin Hohenadler (Universität Würzburg)
Competing Orders in Luttinger and Dirac Liquids
15.11.2017 15:30, Raum: S-403
Dr. Dirk Wulferding (Institute for Condensed Matter Physics, TU Braunschweig and Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science, POSTECH, Korea)
Magnetic force microscopy beyond imaging - from low energy condensed matter physics to high energy particle physics
28.11.2017 17:00, Raum: 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.

11.12.2017 15:45, Raum: S-288
Prof. Avinash Mahajan (Indian Institute of Technology Bombay, Mumbai (India))
Gapless spin liquid behaviour in the S = 1 honeycomb ruthenate Ag3LiRu2O6