[Zurück]

S. Paschen, J. Custers, J. Larrea Jiménez, K. - A. Lorenzer, M. Müller, A. Prokofiev, A. Sidorenko, H. Winkler, A.M. Strydom, Y. Shimura, T. Sakakibara, R. Yu, Q. Si:
"A materials-based global phase diagram for heavy-fermion quantum criticality";
Vortrag: ICM 2012 The 19th International Conference on Magnetism with Strongly Correlated Electron Systems (SCES), Bexco, Busan, Korea (eingeladen); 08.07.2012 - 13.07.2012.

Heavy fermion compounds have in recent years emerged as prototypical quantum critical systems. Studies in
the anisotropic heavy-fermion compound YbRh2Si2 have shown that different types of quantum critical points
(QCPs) are induced by variations of the magnetic field, chemical or external pressure, raising the question of
the extent to which heavy-fermion quantum criticality is universal. We have identified a cubic heavy-fermion
material, Ce3Pd20Si6, as exhibiting a field-induced quantum phase transition as the lower of two consecutive
phase transitions is suppressed to zero. Thus, here the QCP separates two different ordered phases. This transition
is accompanied by an abrupt change of Fermi surface, reminiscent of what happens across the field-induced
antiferromagnetic to paramagnetic transition in YbRh2Si2. From these results we have proposed a materialsbased
global phase diagram that points to the importance of dimensionality - and may serve as guide in the search
for a unified theoretical description [1]. To weaken the lower phase transition temperature and possibly detach
the Kondo destruction scale from the phase transition scale, we are now studying (Ce,La)3Pd20Si6 and Ce3Pd20Si6
under hydrostatic pressure. We acknowledge financial support from the European Research Council (ERC
Advanced Grant No 227378).