TY  - JOUR
AU  - Yang, L. X.
AU  - Rohde, G.
AU  - Chen, Y. J.
AU  - Shi, W. J.
AU  - Liu, Z. K.
AU  - Chen, F.
AU  - Chen, Y. L.
AU  - Rossnagel, K.
AU  - Bauer, Michael
TI  - Experimental evidence for a metastable state in FeTe<sub>1−x</sub>Se<sub>x</sub> following coherent-phonon excitation
JO  - Journal of electron spectroscopy and related phenomena
VL  - 250
SN  - 0368-2048
CY  - New York, NY [u.a.]
PB  - Elsevier
M1  - PUBDB-2021-02576
SP  - 147085 
PY  - 2021
AB  - Changes of the electronic structure of FeTe<sub>1−x</sub>Se<sub>x</sub> (x = 0, 0.3) upon ultrafast excitation with near-infrared laser pulses are investigated using time- and angle-resolved extreme ultraviolet photoemission spectroscopy. At different temperatures and for different doping levels we observe a global oscillation of energy bands near the Fermi energy driven by the coherent excitation of the A<sub>1g</sub>(Te) phonon mode inFeTe<sub>1−x</sub>Se<sub>x</sub>. Prominently, photo-induced band shifts and a spectral weight reduction persist for at least 300 ps, long after the decay of the photo-excited carriers and the damping of the coherent phonons. We argue that the system escapes from the original equilibrium state and is transiently trapped in a possibly metastable state envisioning a purely optical means of manipulating the electronic structure in an iron-based superconductor.  
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000670411800005
DO  - DOI:10.1016/j.elspec.2021.147085
UR  - https://bib-pubdb1.desy.de/record/459472
ER  -