2024-03-28T09:11:09Zhttps://eprints.lib.hokudai.ac.jp/dspace-oai/requestoai:eprints.lib.hokudai.ac.jp:2115/832502022-11-17T02:08:08Zhdl_2115_20045hdl_2115_139Ultrafast dynamics of Mott-state quench and formation in strongly correlated BEDT-TTF molecular conductors observed by three-pulse pump probe spectroscopyTsuchiya, S.Taniguchi, H.Yamada, J.Toda, Y.Mihailovic, D.Mertelj, T.428We investigate the quench and real-time formation of the Mott state and photoexcited carrier relaxation dynamics in the Mott insulator kappa-(BEDT-TTF)(2)Cu[N(CN)(2)]Cl(kappa-Cl) and the superconductor kappa-(BEDT-TTF)(2)Cu[N(CN)(2)]Br(kappa -Br) using three-pulse femtosecond optical spectroscopy, where BEDT-TTF is bis(ethylenedithio)tetrathiafulvalene. In both salts, we find that transient reflectivity amplitude gradually recovers with time after strong near-infrared pulse quench, but its relaxation time is nearly constant throughout. This indicates that in K-Cl, the energy gap for charge excitations is filled rather than closed by photoinduced carriers of only similar to 0.5% per dimer. The Mott state is re-formed on a few-picosecond timescale with the disappearance of the in-gap photodoping-induced states near the Fermi energy. In kappa-Br, a behavior similar to that in kappa-Cl is observed and attributed to the disorder-induced phase-separated Mott insulating regions.American Physical Society (APS)Journal Articleapplication/pdfhttp://hdl.handle.net/2115/83250https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/83250/1/PhysRevB.104.115152.pdf2469-9950Physical Review B104111151522021-09-24enginfo:doi/10.1103/PhysRevB.104.115152Copyright (2021) by The American Physical Society.publisher