Cosmology in Charge Density Wave systems
Event details
| Date | 07.04.2011 |
| Hour | 11:15 |
| Speaker | Prof. D. Mihailovic, Department of Complex Matter Institut |
| Location |
PH L1 503
|
| Category | Conferences - Seminars |
The study of the temporal evolution of systems undergoing symmetry breaking phase transitions¬ whether it is in condensed-matter physics, cosmology or [1]finance ¬is dif[1]ficult because they are hard to repeat, or they occur very rapidly. We report a high-time-resolution study of the evolution of both bosonic and fermionic excitations through an electronic symmetry breaking phase transition. The model system of choice are charge-density-wave materials where phase fluctuations are much slower than amplitude relaxation, which makes modeling significantly easier. Periodically quenching our system with femtosecond optical pulses, we detect hitherto-unrecorded coherent aperiodic undulations of the order parameter, critical slowing down of the collective mode and evolution of the particle–hole gap as the system evolves through the transition. Modelling on the basis of Ginzburg–-Landau theory is used to reproduce the observations without free parameters. Of particular interest is the observation of spectrotemporal distortions arising from spontaneous annihilation of topological defects, analogous to those discussed by the Kibble--Zurek cosmological model.
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Practical information
- Informed public
- Free
Organizer
- ICMP
Contact
- Prof. László Forró