## Fourth meeting

Posted on 11/30/2009

Stephen Keeling volunteered to give us a short overview of what we learned so far. Then, Erhai Zhao gave a gentle overview of the topological insulators and superconductors found in papers:

• Andreas P. Schnyder, Shinsei Ryu, Akira Furusaki, Andreas W. W. Ludwig;

Phys. Rev. B 78, 195125 (2008) and arXiv:0905.2029, AIP Conf. Proc. 1134, 10 (2009)

• Alexei Kitaev, “Periodic table for topological insulators and superconductors”, arXiv:0901.2686

The interest for these subjects is motivated by possible applications in quantum computing.

NOVEMBER**20**

## Third meeting

Posted on 11/30/2009

Dr. Kai Sun from the Joint Quantum Institute (JQI) at the University of Maryland gave a technical but very educational overview of topological insulators. We learned how to characterize topological properties, how topological protection works, and much more (Power Point presentation). Dr. Sun is an expert on quantum liquid crystals and topological phases. He got his PhD from the University of Illinois at Urbana-Champaign in 2009 working with Edurado Fradkin. His papers can be found here.

NOVEMBER**13**

## Second meeting

Posted on 11/16/2009

We discussed the first real topological insulator (invariant under time-reversal) which was proposed to occur and later found to exist in CdTe/HgTe quantum wells. Parag Ghosh led the discussion of the Science article by B. Andrei Bernevig et.al. A …