Kavli colloquium - Amir Yacoby (Harvard university): 'A New Spin on Superfluidity'



15:00 hrs


Building 32, Faculty of Industrial Design Joost van der Grintenzaal


The spin of the electron plays a fundamental role in our understanding of many of the most profound phenomena in condensed matter physics including superconductivity and magnetism. Recently, spin has played a central role in many of the modern topics in condensed matter physics such as the observation and control of topologically protected textures of magnetization known as Skyrmions, topological insulators and superconductors that can host non-Abelian excitations, and perhaps most excitingly in ideas for realizing superfluid transport of spin. Superfluidity describes the property of a fluid to flow unimpeded and without dissipation. In a seminal paper in 1969, Halperin and Hohenberg laid out the foundations for spin superfluidity in magnetic systems and its relation to superfluid Helium. Their theory describes magnetic systems in terms of a condensate of collective spin excitations, however, only now are there concrete ideas of where to search for spin superfluidity and how one might observe unimpeded flow of spins. In this talk I will review some of the underlying physics behind magnetic excitations and spin superfluidity and discuss some of the approaches we have been pursuing to explore them.