Dresden 2017 – scientific programme
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DS: Fachverband Dünne Schichten
DS 42: Metallic Nanowires on Semiconductor Surfaces (jointly with O)
DS 42.1: Talk
Thursday, March 23, 2017, 15:00–15:15, WIL C107
Femtosecond electronic response of photo-excited in situ grown Indium wires — •Mariana Chavez-Cervantes1, Sven Aeschlimann1, Hubertus Bromberger1, Razvan Krause1, Andrea Cavalleri1,2, and Isabella Gierz1 — 1Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany — 2Department of Physics, Clarendon Laboratory, University of Oxford, Oxford, United Kingdom
Strong electronic correlations in one-dimensional wires lead to a metal-to-insulator transition at low temperatures. The low-temperature insulating phase is characterized by a complex order parameter with amplitude (size of the band gap) and phase. Photo-doping with femtosecond laser pulses excites carriers across the band gap and leads to an instantaneous reduction of the amplitude of the order parameter followed by amplitude and possibly phase oscillations. We have grown one-dimensional indium wires in situ on a Si(111) substrate and characterized them with low-energy electron diffraction (LEED) and angle-resolved photoemission spectroscopy (ARPES). At room temperature the system exhibits three one-dimensional metallic bands that undergo a complex metal-to-insulator transition at T=110K. We excited the indium wires with intense femtosecond pulses at 1.5eV and probed the response of the electronic structure with time-resolved ARPES at extreme ultraviolet wavelengths. We analyze the dynamics of the complex order parameter and the energy-dependence of the photo-excited population life time.