“Specific Heat Capacity Measurements on Uniaxially Pressurised Sr2RuO4” by Clifford Hicks (Max Planck Institute for Chemical Physics of Solids, Dresden)

Wednesday, January 10, 2018 - 4:00pm
Condensed Matter Physics Seminar

Uniaxial stress can be used as a strong, continuously tunable perturbation of electronic materials. Over the past few years we have shown that uniaxial pressures of ~1 GPa drive the critical temperature Tc of the superconductor Sr2RuO4 through a pronounced peak, at which it is more than double its value in the unstressed material. This peak is most likely associated with tuning one of the Fermi surfaces through a topological transition, and associated Van Hove singularity in the density of states. In my talk I will discuss how physical properties that we have so far been able to measure vary across this singularity, focusing on specific heat capacity. We are moving towards quantitatively precise measurement of the specific heat capacity of uniaxially stressed samples. In superconductors, the heat capacity jump at Tc provides key thermodynamic information. In Sr2RuO4, we find that the heat capacity jump at Tc is not strongly affected by uniaxial stress, except very close to the Van Hove singularity.

If time and experimental circumstances permit, I will also present data on the effects of uniaxial stress on the superconductivity of YBa2Cu3O6+x, and on the structural transition of FeSe.

PAB 4-330