Prof. Dragan Mihailović: Cosmology in the Laboratory: Higgs Bosons and the Kibble-Zurek Cosmological Scenario in Elecronic Crystals

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   Cosmology in the Laboratory: Higgs Bosons and the Kibble-Zurek Cosmological Scenario in Elecronic Crystals

   Prof. Dragan Mihailović, Institut Jožef Stefan in FMF Univerze v Ljubljani 

Fundamental problems in the temporal evolution of phase transitions span subjects from condensed matter to high energy physics and cosmology. The topics are closely interconnected both conceptionally and historically, extending even to brain function and finance. Following the suggestion by Zurek in 1985 of a possible "laboratory cosmology experiment" to test Kibble's cosmological model, in this coloquium, I will report on a high-resolution real-time study of the non-equillibrium evolution of both bosonic and fermionic excitations through a second order charge-ordering transition in electronic crystals. Using a new multi-pulse femtosecond spectroscopy technique, we quench the model system into the high-symmetry state, and then detect coherent aperiodic undulations of the order parameter, critical slowing down of the collective mode, and evolution of the particle-hole gap which appears through the Peierls-BCS mechanism (akin to the Higgs mechanism) as it evolves through the transition. Numerical modeling convincingly reproduces the observations, including the spatio-temporal distortions caused by Higgs bosons arising from spontaneous annihilation of topological defects, providing new data on hitherto unexplored dynamics of both single particle and collective excitations through symmetry breaking transitions.