Past Events

Abstract:

I will review some of my recent projects in the field of superconductivity based on thermodynamic measurements under extreme conditions, such as high magnetic fields, high pressure, on tiny samples and with ultra-high precision. This comprises the discovery of a high magnetic field induced Fulde-Ferrell-Larkin-Ovchinnikov state in organic superconductors, an unusual Berezinskii-Kosterlitz-Thouless-like superconducting transition in arrays of weakly coupled quasi-1d superconducting chains (e.g. bundles and arrays of ultra-thin carbon nanotubes) and high pressure induced bulk superconductivity in some members of the pnictide compounds. I will furthermore demonstrate how thermodynamic methods can be used as a ‘thermal spectroscopy’ in order to collect detailed information about superconductors which is usually only available from neutron scattering and real spectroscopic experiments.

About the Speaker:

Dr. Rolf Lortz is an expert on calorimetric techniques in superconductors. He received his PhD in 2002 from the University of Karlsruhe in Germany (having worked on the effect of phase fluctuations in the high-Tc YBCO), before moving to the University of Geneva in Switzerland in 2003. Here, he continued his work on a range of exotic superconductors. Most notably, he discovered the first evidence for a Fulde-Ferrell-Larkin-Ovchinnikov state in an organic superconductor. In 2008 he took up a position as assistant professor in the Department of Physics at HKUST. Since then, he has succeeded in detecting the thermodynamic signature of superconductivity in ultra-thin carbon nanotubes. He is currently searching for universality in other quasi-one-dimensional superconductors, as well as doing high pressure calorimetric experiments on pnictide superconductors.

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Physics colloquium series is organized to introduce cutting edge researches and new development in physics, designed to be suitable to graduate and undergraduate students, and also to scientists working on different fields. Each colloquium will generally start with an extensive introduction of the background of the field, followed by forefront research topics and results. The colloquium will serve as an education forum for students and laymen alike, and also serve as a platform for exchange and update their knowledge of various branches of physics among academic staff members.

Coffee and tea will be served 20 minutes prior to the Colloquium.