High pressure Fermi Surface measurements of the High Temperature Superconductor YBaCuO*

Many quantum materials exhibit similar phase diagrams at low temperature, leading to a great deal of interest into a common mechanism for a ``universal phase diagram''. The typical ingredients of such phase diagrams include an antiferromagnetic phase, a superconducting dome, and possibly one, or several quantum critical points. Temperature versus chemical doping is one traditional way to look at such materials, however thermodynamic variables such as magnetic field or hydrostatic pressure have proved to be powerful tools to explore this phase diagram. Our group performed static high pressure SdH fermiology studies of YBCO at He-3 temperatures to fields of 70 T using an RF tank circuit based on a tunnel diode oscillator.