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DTSTAMP:20240328T123000Z
UID:https://www.fhi.mpg.de/events/25255/72594
DTSTART:20200709T130000Z
CLASS:PUBLIC
CREATED:20200703T081112Z
DESCRIPTION:Change notice: PC Online Talk\nTime- and angle-resolved photoel
ectron spectroscopy (trARPES) is a very powerful technique to investigate
the transient electronic band structure and the fundamental scattering pro
cesses in solid state materials\, combining the direct momentum- and energ
y-resolved view on the electronic structure provided by ARPES with the add
itional dimension of femtosecond time resolution. This also opens up a new
horizon compared to conventional ARPES\, namely the spectroscopy of forme
rly unoccupied states above the chemical potential\, which can be transien
tly populated and subsequently studied. Challenges posed by the necessary
extreme ultraviolet (XUV) photon energy to cover the whole Brillouin zone
(BZ) in electron momenta have been tackled by new laser developments\, all
owing for operation at high repetition rates and providing the necessary h
igh sensitivity to such unoccupied states throughout the BZ [1\,2]. Combin
ing such advanced laser sources with the recently developed time-of-flight
based momentum microscopes\, which promise a huge improvement in parallel
detection efficiency and allow for the simultaneous detection of multiple
BZ without the need to rearrange the sample geometry [3] seems like an id
eal match.Recently\, we upgraded our OPCPA-driven high-repetition rate XUV
setup at the FHI\, which now combines both a hemispherical analyzer and a
time-of-flight momentum microscope (SPECS Metis 1000) in the same experim
ental chamber. In my talk\, I will present the various possibilities enabl
ed by the new instrumentation\, like movies of the whole transient Fermi s
urface\, observation of anisotropic scattering dynamics\, analysis of dich
roism in the momentum distribution and more. In addition\, I will quantify
the advantages and limitations of both hemispherical analyzer and momentu
m microscope for certain use cases in the field of trARPES and discuss the
advantage of combining both types of instruments within a single experime
ntal apparatus. [1] M. Puppin\, et al.\, Opt. Express 23\, 1491 (
2015)[2] M. Puppin\, et al.\, Rev. Sci. Instrum. 90\, 023104 (201
9).[3] G. Schönhense\, et al.\, J. Electron Spectrosc. Relat. Ph
enom. 200\, 94–118 (2015).\nSpeaker: Dr. Laurenz Rettig
LAST-MODIFIED:20200703T081112Z
LOCATION:
ORGANIZER:
SUMMARY:Sailing transient k-space – Is there a perfect spectrometer for t
ime-resolved ARPES
URL:https://www.fhi.mpg.de/events/25255/72594
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