BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//UNIFR/WEBMASTER//NONSGML v1.0//EN
CALSCALE:GREGORIAN
BEGIN:VEVENT
DTSTART;VALUE=DATE:20210922T165000
DTEND;VALUE=DATE:20210922T165000
UID:9927@agenda.unifr.ch
DESCRIPTION:An excited electron in condensed matter propagates with its momentum\nk at an energy E k ) and experiences\nelastic and inelastic scattering processes, which lead to relaxation. Experiments employing f emtosecond\ntime resolved photoelectron spectroscopy exploited so far very successfully the surface sensitivity of photo\nelectron spectroscopy and probed such scattering processes locally at the surface or the surface near region in the\ntime domain [1]. Here, we report on experimental results which analyze the non local dynamics of excited\nelectrons propagating through laye r stacks using two photon photo electron emission spectroscopy (2PPE). In\nthese experiments one photon excites in a Au/Fe/MgO(001) heterostructure electrons in Fe. Electron propagation\nth rough the layer stack to the Au surface is detected in 2PPE in back pump front probe experiments 2 ]], similar\nto pioneering femtosecond pump probe experiments in condensed matter, which revealed time dependent\nchanges in the linear optical reflectivity of free standing Au films [ 3 We observe pronounced differences\nbetween front and back pumping the hetero structure which are attribu ted to superdiffusive electron transport 4 ]\ncontributions through the layer stack Furthermore, we investigate the relaxation of electronic excitation s in the\ncharge density wave / Mott system 1 T TaS 2 with femtosecond photoelectron sp ectroscop y 5 ,6 ]]. In such Mott\nsystems double electron popu lation of single sites represe nt doublo n e xcitatio ns and the u ltrafast doublon\ndynamics including scattering of Bloch electrons with doublon excitations will be discus sed\nThis work was funded by the Deu\ntsche Forschungsgemeinschaft through the Collaborative Research Center\nCRC 1242 (project number 278162697)\n[1]\nU. Bovensiepen, H. Petek, M. Wolf, Dynamics at Solid State Surface and Interfaces\nVol. 1, Wiley VCH, 2010.\n[\n2 Y. Beyazit, J. Beckord, P. Zhou, J. P. Meyburg, F. Kühne, D. Diesing, M. Ligges, U . Bovensiepen\nPhys. Rev. Lett. 12 5 , 076803 20 20\n[\n3 S. D. Brorson, J. G. Fujimoto, E. P. Ippen, Phys. Rev. Lett. 59 , 1962 (\n[\n4 M. Battiato, K. Carva, P. M. Oppeneer, Phys. Rev. B 86 , 024404 (\n[\n5 M. Ligges, I. Avigo, D. Golez, H. U. R. Strand, Y. Beyazit, K. Hanff, F. Diekmann, L. Stojchevska, M.\nKalläne, K. Rossnagel, M. Eckstein, P. Werner, U. Bovensiepen, Phys. Rev. Lett. 120 , 166401 2018\n[\n6 I. Avigo, F. Queisser, P. Zhou, M. Ligges, K. Rossnagel, R. Schützhold, U. Bovensiepen,\nPhys. Rev. Research 2 , 0 2 2 04 6 R 20 20
SUMMARY:Dynamics of propagating and localized electronic excitations in con densed matter systems analyzed by femtosecond photoelectron spectroscopy
CATEGORIES:Colloque / Congrès / Forum
LOCATION:PER 08\, 0.51 Grande auditoire\, Chemin du Musée 3\, 1700 Fribourg
URL;VALUE=URI:https://agenda.unifr.ch/e/fr/9927
END:VEVENT
END:VCALENDAR