From Wednesday up to today I attended the International conference on Topological Quantum Phenomena 2012 in Nagoya. This is one of the meetings held as part of the ministry of education (MEXT) funded five-year program headed by Yoshi Maeno, combining efforts in condensed matter all related by exploring topologically non-trivial states of matter, comprising several research groups in multiple locations in Japan. The plenary talks were presented by Grigori Volovik, Yoichi Ando, Tony Leggett and Shoucheng Zhang, and the scope is indeed rather broad.

Now topological things have always been important ever since Dirac proposed his monopole, but remained usually outside the real mainstream physics. Also, the focus has been mostly on topological defects, which are localized excitations that nevertheless influence the whole system. However, since the discovery of the (fractional) quantum Hall effect, we know that there can also be topological ground states, such that the systems themselves can only be understood by regarding them as a whole, as opposed to having a local order parameter. After so-called topological insulators were predicted and then found a couple of years ago, it seems that topological has become a real buzzword. For me this is interesting, as from my Master’s thesis on I’ve worked on topological stuff.

As pointed out by Volovik already in the first talk, it seems that topology is a necessary ingredient in the general classification scheme of states of matter, which is the principal task of condensed matter physics. So on top of the broken-symmetry paradigm, topological non-trivial aspects need to be taken into account for a full understanding. Moreover, some old knowledge may be better formulated in topology language. According to Volovik, the Fermi surface itself is topologically non-trivial. By the way, his famous book The Universe in a Helium Droplet is very instructive and the draft is freely available.

Overall it was a nice conference with a broad scope that nevertheless seemed to belong to the same endeavour. The scale was quite right with just over 100 people attending on average per day. The interactions during the poster sessions—sometimes a dull affair—were particularly lively. Unfortunately, the deadline for submission was before my arrival in Japan, but I had some interesting discussions anyway.

On Friday there was an excursion to the very large Higashiyama zoo and to Nagoya castle. The latter was destroyed by incendary bombing in 1945, but has been rebuilt in ferroconcrete. Of the cuisinse in particular kochin, a local breed of chicken, was especially good.

© 2012 Aron Beekman Suffusion theme by Sayontan Sinha