really is another ballgame than the rest of physics] and I'm proud that I was able to learn it. Zaanen was a visiting professor of Theoretical Physics at the Ecole Normale Superieur, Paris, France. In 2012 and 2013 he respectively was a Solvay Professor of Physics at the Solvay Institute, Brussels, Belgium and a fellow of the Newton Centre at the University of Cambridge. At present he is Professor of theoretical physics at Leiden University. Since 2012 Zaanen is member of the Royal Netherlands Academy of Arts and Sciences. High-temperature superconductivity Recently Zaanen is known for his contribution to the understanding of high-temperature superconductivity. In most high-temperature superconductors the copper atoms are arranged in thin layers. Each atom has its own magnetic field which is opposite to that of its neighbor. Electrons can scarcely move in such an environment, as they are also magnetic. Recently, Zaanen and colleagues Cubrovic and Schalm applied string theory to explain a physical phenomenon. Initially their use of string theory attracted a lot of criticism. However, in recent years an increasing amount of experimental evidence has been collected in its favor. Its latest accomplishment is the development of the AdS/CFT correspondence theory, sometimes called Maldacena duality or gauge/gravity duality. Once it was realised that AdS/CFT could be applied to a broader spectrum of physical phenomena, Zaanen was inspired to use these ideas for his own area of High-temperature superconductivity. Zaanen stated: "It has always been assumed that once you understand this quantum-critical state, you can also understand high temperature super-conductivity. But, although the experiments produced a lot of information, we hadn't the faintest idea of how to describe this phenomenon. We hadn't expected it to work so well, the maths was a perfect fit; it was superb. When we saw the calculations, at first we could hardly believe it, but it was right." Other areas of involvement General relativity and string theory Fermion minus sign problem Stripe microscopy and Stripe fractionalisation Geometrical order in Luttinger liquids Duality in quantum elasticity: quantum liquid crystals and cosmology Quantum criticality Recent publications A. Mesaros, K. Fujita, H. Eisaki, J.C. Davis, S. Sachdev, J. Zaanen, E.-A. Kim and M. Lawler, How topological defects couple the smectic and nematic electronic structure of the cuprate pseudogap states, Science, 426 (2011). R.J. Slager, A. Mesaros, V. Juricic and J. Zaanen, The space group classification of topological band-insulators, Nature Physics, 98 (2013). Y.