Publications (7)
First experiments with ultrashort, circularly polarized soft X-ray pulses at FLASH2
S. Marotzke, D. Gupta, R. -P. Wang +23
Time-resolved absorption spectroscopy as well as magnetic circular dichroism with circularly polarized soft X-rays (XAS and XMCD) are powerful tools to probe electronic and magneti…
Optical control of 4f orbital state in rare-earth metals
N. Thielemann-Kühn, T. Amrhein, W. Bronsch +28
A change of orbital state alters the coupling between ions and their surroundings drastically. Orbital excitations are hence key to understand and control interaction of ions. Rare…
Ultrafast modification of the electronic structure of a correlated insulator
O. Grånäs I. Vaskivskyi, X. Wang, P. Thunström +25
A non-trivial balance between Coulomb repulsion and kinematic effects determines the electronic structure of correlated electron materials. The use electromagnetic fields strong en…
Simultaneous mapping of the ultrafast time and fluence dependence of the laser-induced insulator-to-metal transition in magnetite
J. O. Schunck, P. S. Miedema, R. Y. Engel +10
Pump-probe methods are a ubiquitous tool in the field of ultrafast dynamic measurements. In recent years, x-ray free-electron laser experiments have gained importance due to their…
Two-color operation of a soft x-ray FEL with alternation of undulator tunes
E. A. Schneidmiller, I. J. Bermudez Macias, M. Beye +13
FLASH is the first soft X-ray FEL user facility, routinely providing brilliant photon beams for users since 2005. The second undulator branch of this facility, FLASH2, is gap-tunab…
Balanced Detection in Femtosecond X-ray Absorption Spectroscopy to Reach the Ultimate Sensitivity Limit
W. F. Schlotter, M. Beye, S. Zohar +21
X-ray absorption spectroscopy (XAS) is a powerful and well established technique with sensitivity to elemental and chemical composition. Despite these advantages, its implementatio…
Ultrafast melting of a charge-density wave in the Mott insulator 1T-TaS2
S. Hellmann, M. Beye, C. Sohrt +11
Femtosecond time-resolved core-level photoemission spectroscopy with a free-electron laser is used to measure the atomic-site specific charge-order dynamics in the charge-density-w…