"More is different" - how states of matter emerge from quantum theory

John Chalker will review the quantum mechanics of identical particles which forms the foundation for our understanding of why diamond is transparent and why gold conducts electricity. He will also explain how we can control the motion of electrons in certain devices to make resistances quantised with an accuracy of a few parts in a billion.

Fabian Essler will discuss the hugely successful framework for classifying possible states of quantum matter, pioneered by the great Russian Nobel Laureate, Lev Landau. This framework is conceptually remarkably simple, but is broad enough to describe physics ranging from magnets to superconductors to fundamental physics in the guise of relativistic quantum field theory and the Higgs phenomenon.

Steve Simon will focus on the recent realization that Landau’s classification, thought to be complete for most of the twentieth century, in fact misses some of the most exciting, yet subtle, physics. The new missing ingredient is naturally cast in the language of the mathematical field of topology, giving rise to a host of what we now call topological states of matter. In particular, we have now realized that fundamentally new types of electronic materials exist --- some of which, in fact, have been hiding under our noses for decades!