@article{3d1af367d89641f6aeff3bd7002fe8ae,
title = "A setup for extreme-ultraviolet ultrafast angle-resolved photoelectron spectroscopy at 50-kHz repetition rate",
abstract = " Time- and angle-resolved photoelectron spectroscopy (trARPES) is a powerful method to track the ultrafast dynamics of quasiparticles and electronic bands in energy and momentum space. We present a setup for trARPES with 22.3 eV extreme-ultraviolet (XUV) femtosecond pulses at 50-kHz repetition rate, which enables fast data acquisition and access to dynamics across momentum space with high sensitivity. The design and operation of the XUV beamline, pump-probe setup, and ultra-high vacuum endstation are described in detail. By characterizing the effect of space-charge broadening, we determine an ultimate source-limited energy resolution of 60 meV, with typically 80-100 meV obtained at 1-2 × 10 10 photons/s probe flux on the sample. The instrument capabilities are demonstrated via both equilibrium and time-resolved ARPES studies of transition-metal dichalcogenides. The 50-kHz repetition rate enables sensitive measurements of quasiparticles at low excitation fluences in semiconducting MoSe 2 , with an instrumental time resolution of 65 fs. Moreover, photo-induced phase transitions can be driven with the available pump fluence, as shown by charge density wave melting in 1T-TiSe 2 . The high repetition-rate setup thus provides a versatile platform for sensitive XUV trARPES, from quenching of electronic phases down to the perturbative limit.",
author = "Buss, {Jan Heye} and He Wang and Yiming Xu and Julian Maklar and Frederic Joucken and Lingkun Zeng and Sebastian Stoll and Chris Jozwiak and John Pepper and Chuang, {Yi De} and Denlinger, {Jonathan D.} and Zahid Hussain and Alessandra Lanzara and Kaindl, {Robert A.}",
note = "Funding Information: We gratefully acknowledge A. Federov, W. Zhang, S. Ulon-ska, and B. V. Smith for contributions during commissioning, J. Wu and S. Tongay for providing TMD samples, and P. Richard for access to software macros. Moreover, we thank R. W. Schoenlein, H. Ding, and F. Parmigiani for many stimulating discussions. This work was primarily funded by the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division under Contract No. DE-AC02-05-CH11231 (Ultrafast Materials Science Program No. KC2203) covering the design and construction of the trARPES setup as well as equilibrium and ultrafast studies (J.H.B., H.W., Y.X., J.M., F.J., L.Z., S.S., A.L., and R.A.K.). The cryostat was developed and input into the UHV design provided by the Advanced Light Source (C.J., J.P., Y.D.C., J.D., and Z.H.), which is a DOE Office of Science User Facility supported under Contract No. DE-AC02-05-CH11231. J.H.B. gratefully acknowledges a postdoc fellowship from the German Research Foundation (DFG), and J.M. and S.S. acknowledge student fellowships from the German Academic Exchange Service. Publisher Copyright: {\textcopyright} 2019 Author(s).",
year = "2019",
month = feb,
day = "1",
doi = "10.1063/1.5079677",
language = "English (US)",
volume = "90",
journal = "Review of Scientific Instruments",
issn = "0034-6748",
publisher = "American Institute of Physics Publising LLC",
number = "2",
}