Regensburg 2019 – scientific programme

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O: Fachverband Oberflächenphysik

O 95: Semiconductor Substrates: Metallic Nanowires

O 95.10: Talk

Friday, April 5, 2019, 12:45–13:00, H14

Charge density wave melting in one-dimensional wires with femtosecond sub-gap excitation — •Mariana Chávez-Cervantes, Gabriel E. Topp, Sven Aeschlimann, Rǎzvan Krause, Shunsuke A. Sato, Michael A. Sentef, and Isabella Gierz — Max Planck Institute for the Structure and Dynamics of Matter

Charge density waves (CDWs) are symmetry-broken ground states that commonly occur in low-dimensional metals due to strong electron-electron and /or electron-phonon coupling. The non-equilibrium carrier distribution established via photodoping with femtosecond laser pulses readily quenches these ground states and induces an ultrafast insulator-to-metal phase transition. To date, CDW melting has been mainly investigated in the single-photon and tunneling regimes, while the intermediate multi-photon regime has received little attention. Here we excite one-dimensional indium wires with a CDW gap of  300 meV with mid-infrared pulses at 190 meV with MV/cm field strength and probe the transient electronic structure with time- and angle-resolved photoemission spectroscopy (tr-ARPES). We find that the CDW gap is filled on a timescale short compared to our temporal resolution of 300 fs and that the phase transition is completed within  1 ps. Supported by a minimal theoretical model we attribute our findings to multi-photon absorption across the CDW gap.