Speaker
Description
$\textbf{Attosecond time-resolved experiments at a seeded free electron laser}$
Praveen Kumar Maroju$^{1,2}$ , Michele Di Fraia$^{3}$, Oksana Plekan$^{3}$, Matteo Bonanomi$^{4,5}$, Barbara Merzuk$^{1}$, David Busto$^{1,2}$, Ioannis Makos$^{1}$, Marvin Schmoll$^{1}$, Ronak Shah$^{1}$, Primož Rebernik Ribič$^{3}$, Luca Giannessi$^{3,6}$, Giovanni De Ninno$^{3,7}$, Carlo Spezzani$^{3,7}$, Giuseppe Penco$^{3}$, Alexander Demidovich$^{3}$, Miltcho Danailov$^{3}$, Marcello Coreno$^{3,6,8}$, Marco Zangrando$^{3,9}$, Alberto Simoncig$^{3}$, Michele Manfredda$^{3}$, Richard J. Squibb$^{10}$, Raimund Feifel$^{10}$, Samuel Bengtsson$^{2}$, Emma Rose Simpson$^{2}$, Tamás Csizmadia$^{11}$, Mathieu Dumergue$^{11}$, Sergei Kühn$^{11}$, Kiyoshi Ueda$^{12}$, Jianxiong Li$^{13}$, Kenneth J. Schafer$^{13}$, Fabio Frassetto$^{14}$, Luca Poletto$^{14}$, Kevin C. Prince$^{3}$, Johan Mauritsson$^{2}$, Carlo Callegari$^{3}$ & Giuseppe Sansone$^{1}$
$\small{^1Physikalisches \,Institut, Albert-Ludwigs-Universität\, Freiburg, Freiburg, Germany.}$
$\small{^2Department\, of\, Physics, Lund\, University, Lund, Sweden.}$
$\small{^3Elettra-Sincrotrone\, Trieste, Basovizza, Trieste, Italy. }$
$\small{^4Dipartimento\, di\, Fisica\, Politecnico, Milan, Italy. }$
$\small{^5Istituto\, di\, Fotonica\, e Nanotecnologie CNR-IFN, Milan, Italy.}$
$\small{^6INFN Laboratori Nazionali di Frascati, Frascati, Italy.}$ $\small{^7Laboratory of Quantum Optics, University of Nova Gorica, Nova Gorica, Slovenia. }$
$\small{^8ISM-CNR, Istituto\, Struttura\, della\, Materia, Trieste, Italy.}$ $\small{^9IOM-CNR, Basovizza, Trieste, Italy.}$ $\small{^{10}Department\, of\, Physics, University\, of\, Gothenburg, Gothenburg, Sweden.}$
$\small{^{11}ELI\,ALPS, ELI-HU\, Non-Profit\, Ltd., Szeged, Hungary.}$ $\small{^{12}Department\, of\, Chemistry, Tohoku\, University\,, Sendai 980-8578, Japan. }$
$\small{^{13}Department\, of\, Physics\, and\, Astronomy, Louisiana\, State\, University, Baton\, Rouge, LA, USA.}$
$\small{^{14}Istituto\, di\, Fotonica\, e\, Nanotecnologie, CNR, Padova, Italy.}$
Abstract
Investigation of valence and core electron dynamics on their natural time scale requires attosecond pulses. Routinely, these dynamics are probed via pump-probe schemes using phase-locked extreme ultraviolet (XUV) attosecond pulses generated using the high harmonic generation (HHG) scheme and the infrared (IR) pulses driving the HHG process. Free electron lasers (FELs) on the other hand are an alternative source of radiation spanning the XUV to X-ray spectral regions with unprecedented intensities. However, until recently$^{1,2}$, time-resolved studies at FELs were limited to a few femtosecond timescales owing to unavailability of attosecond pulses at these FEL facilities. Here, we will present the results of experiments performed at the seeded FEL FERMI, where we demonstrate generation and characterization of attosecond pulse trains$^{2}$. In the scheme, attosecond pulse trains were produced using the temporal beating of the multiple (three/four) phase-locked harmonics generated at FERMI and are characterized using Correlation Based Reconstruction of Attosecond pulses (CoBRA), inspired from Reconstruction of Attosecond Beating By Interference of Two-photon transitions (RABBIT) scheme. Further, we introduce a novel single-shot timing-tool to determine the relative synchronization between the attosecond pulse train and the optical oscillations of the IR field, with a temporal resolution down to a few tens of attoseconds. Using the timing-tool, for the first time, we demonstrate attosecond coherent control of photoionization in XUV-IR two-color fields by manipulating the phase of the high-order IR transitions at the seeded FEL FERMI$^{3}$.
References
1. Duris, J. et al. Nat. Photon.14, 30–36 (2020)
2. Maroju, P. K. et al. Nature 578, 386–391 (2020)
3. Maroju, P.K. et al. Nat. Photon. 17, 200–207 (2023)
