Department Seminar: Jaka Vodeb, Friday, 25.5.2018 at 13:00
Charged lattice gas of polarons in 1T-TaS2
Jaka Vodeb, Department of Complex Matter, JSI
Friday, 25.5.2018 at 13:00 in the F7 Seminar room
Motivation for this work comes from the discovery of a new metastable amorphous (A) state in 1T-TaS2 (TAS)1. The A state represents a disordered polaron pattern, which exhibits metallic behavior. We employed a classical charged lattice gas of polarons with screened Coulomb interaction and a fixed polaron concentration as a model for the A state. The idea has been used successfully in the work of Brazovskii2 who first proposed the model and used it to model the commensurate state. Karpov et al.3 also used it to model the hidden state, observed in TAS4. Our work has shown that the A state can be successfully modeled using classical charged polarons. Further investigation of the model has shown that there exists an infinite number of crystalline phases within the model as a function of polaron concentration. There also exist other amorphous phases which lie in between the crystalline phases. They exhibit glassy behavior and in contrast to the current paradigm of glass formation5 appear to be the ground state of the system.
1.Gerasimenko, Y. et al. Ultrafast jamming of electrons into an amorphous entangled state. arXiv preprint arXiv:1803.00255 (2018).
2.Brazovskii, S. Modeling of Evolution of a Complex Electronic System to an Ordered Hidden State: Application to Optical Quench in 1T-TaS2. Journal of Superconductivity and Novel Magnetism 28, 1349–1353 (2015).3.Karpov, P. & Brazovskii, S. Modeling of networks and globules of charged domain walls observed in pump and pulse induced states. Scientific reports 8, 4043 (2018).4.Stojchevska, L. et al. Ultrafast switching to a stable hidden quantum state in an electronic crystal. Science 344, 177–180 (2014).5.Debenedetti, P. G. & Stillinger, F. H. Supercooled liquids and the glass transition. Nature 410, 259 (2001).