Dragan Mihailovich (Special Seminar)

Date(s) - Feb 12 2014
10:30 AM - 11:30 AM

Room 335, McCullough Building


Prof. Dr. Dragan D. Mihailovic

Chief scientist at “Jozef Stefan” Institute, and Professor at the University of Ljubljana, Slovenia



 Trajectories through phase transitions in time: From oscillating order to topologically protected hidden states



 New techniques in time-resolved optical spectroscopy allow us to investigate phase transitions under controlled, yet highly non-ergodic conditions. The measurement of the temporal evolution of not only single particle and collective excitations, but also topological excitations through the transition lead to a new insight into the emergence of functional properties under non-equilibrium conditions.  The experiments on well-known rare earth tellurides and transition metal chalcogenides which I will discuss reveal some unexpected phenomena. Femtosecond coherent oscillations of the order parameter and the subsequent creation and annihilation of topological defects lead to the emission of detectable Higgs-like amplitude waves. Most remarkably, switching to a stable, topologically protected state can occur under specific conditions, opening a route to the creation of hidden states.  Such switching at unprecedented speed between charge ordered states indicates a potential for ultrafast non-volatile memory technology.


 R. Yusupov et al Nat. Phys. 6, 681 (2010)


L. Stojchevska et al., cond-mat (2014)