Despite uranium uniqueness, such complete results pave the way for studies of strongly correlated electronic systems which exhibit a competition between ground states, sometimes surprising.
Figure: Fermi surface topology (section) of uranium calculated at ambient pressure (top) and 20GPa (bottom). The different colors correspond to the different sheets of the Fermi surface.
Phonon dispersion as a function of pressure was measured by inelastic X-Ray scattering at ESRF (ID287 beamline). The full agreement with the theory by Johann Bouchet from CEA/DAM enabled a more detailed study of electron-phonon coupling, which reveals as the key factor governing CDW stabilization below 1.5GPa. In contrast to the common explanation involving a variation in the nesting of the Fermi surface: there is almost no change from 0 to 20GPa (Figure) To end with, the pressure dependence of the superconducting critical temperature was modelled in excellent agreement with experiment.
This work has been done in collaboration between SPSMS, CEA/DAM, ESRF, UPMC and LANL (USA).