Quantum criticality points - heavy fermions and beyond
Event details
| Date | 16.11.2012 |
| Hour | 11:00 |
| Speaker | Prof. Silke Bühler - Paschen, Institute of Solid State Physics, Vienna University of Technology |
| Location | |
| Category | Conferences - Seminars |
Temperature agitates. To bring matter to a quiet and well defined state it is necessary to cool it down. Yet, there are situations in which certain degrees of freedom resist freezing out and remain violently fluctuating even at absolute zero in temperature. This phenomenon of “quantum criticality” has been reported in distinct systems such as high-temperature superconductors, heavy fermion compounds, metamagnets, ferroelectrics, 3He films, quantum dots, or cold atom systems and is a topic of intense worldwide research. This talk will spotlight heavy fermion compounds which have in recent years emerged as prototypical quantum critical systems. Studies in anisotropic heavy-fermion compounds have shown that different types of quantum critical points (QCPs) may be induced by the variation of different control parameters (magnetic field, chemical or external pressure), raising the question of the extent to which heavy-fermion quantum criticality is universal. Recently, we have made the unexpected observation of a cubic heavy-fermion material exhibiting a QCP that is accompanied by an abrupt change of Fermi surface. Previously, this kind of QCP was believed to require reduced dimensionality. From these results we have proposed a materials-based global phase diagram for heavy fermion compounds that points to the importance of dimensionality - and may serve as guide in the search for a unified theoretical description [1].
[1] J. Custers, K.-A. Lorenzer, M. Müller, A. Prokofiev, A. Sidorenko, H. Winkler, A. M. Strydom, Y. Shimura, T. Sakakibara, R. Yu, Q. Si, and S. Paschen, Nature Materials 11, 189 (2012).
[1] J. Custers, K.-A. Lorenzer, M. Müller, A. Prokofiev, A. Sidorenko, H. Winkler, A. M. Strydom, Y. Shimura, T. Sakakibara, R. Yu, Q. Si, and S. Paschen, Nature Materials 11, 189 (2012).
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Practical information
- Informed public
- Free
Organizer
- ICMP (Arnaud Magrez)
Contact
- Prof. L. Forrò