PostDoc in X-ray science studying isolated atoms and molecules, Uppsala University, Sweden

Post Doc in research on Low Density Matter using pulsed XUV and X-rays sources
We are looking for a talented Post Doc in the field of research using XUV and X-rays to study
Low Density Matter (LDM). The position is for 1+1 year and located at the Division of
Molecular and Condensed Matter Science, Department of Physics and Astronomy, Uppsala

The research will be conducted in two different, but closely related, fields.
1. Time-integrated measurements
These experiments will primarily be conducted using Resonant Inelastic X-ray
Spectroscopy (RIXS). The Division of Molecular and Condensed Matter Science have led
the development of the VERITAS beamline at the MAX-IV synchrotron in Lund. At VERITAS
we will perform high-resolution RIXS measurements focusing on small molecular
systems, examples of areas that will be pursued are given in Refs. [1], [2]. You will be an
integral part in performing these novel experiments and also test new concepts for the
sample delivery system at VERITAS. Initially this research will be focused on inversion
symmetric molecules, parity changes, ultrafast processes and all will be accessed through
high resolution RIXS spectroscopy.

2. Time-resolved experiments
Time-resolved experiments will be conducted both at the European X-FEL (EuXFEL) and
in our home-lab where XUV radiation is produced using HHG, see eg. [3]–[5].
a. Some of the science performed at EuXFEL will be based on our experience with
stimulated X-ray emission at said source [6]. Based on this we foresee several
experiments using the same technique (pioneered by us in the X-ray regime) as well
as electron, ion and X-ray photon spectroscopies. You will be an integral part in
performing these experiments, developing the methods further, analyzing results
and writing papers.
b. We are in the final process of installing an X-ray photon spectrometer (similar to, but
still very different from that used at VERITAS), with inherent time-resolution, at the
SQS instrument at the EuXFEL. The successful candidate will be a part of the final
stages of commissioning as well as the first experiments using this spectrometer.
c. In parallel with the above outlined directions we conduct research in our home-
based HHG laboratory where we primarily use photoelectron spectroscopy
(XPS/UPS) to study the time-evolution of photo-excited atomic and molecular
systems. This has recently become possible in our home-lab and we are now
exploring the possibilities using the angular resolution offered by the ARTOF-2 [5] in
conjunction with pump-probe experiments on LDM samples where the initial
experiments are planned for fall 2020 (now).

As a Post Doc you will off course be encouraged to suggest and pursue your own research
ideas in parallel with the ongoing activities.

The ideal candidate has:
- A Ph. D. in physics or chemistry with a specialization that is related to the above outlined
- Experience in research with XUV and/or X-rays
- Experience with vacuum generation and research in vacuum
- Experience using at least one of the techniques XPS/UPS and RIXS
- Experience with research in LDM science
- Experience with at least one of the following laser sciences, HHG, synchrotron science
and/or XFEL science.

The position will remain open until a suitable candidate is found and will then be immediately
closed. We are somewhat flexible with the starting date, especially to accommodate for
COVID-19 related issues.

Information about:
- Uppsala university:
- Department of Physics and Astronomy:
- The Division of Molecular and Condensed Matter Science
Questions, enquires and your application should be sent to:

Your application should contain:
- A personal letter describing your research interests and reasons for applying for this
Post Doc. Here you should also state when you can join us on site in Uppsala.
- A CV including date for obtaining your Ph. D. (can also be planned in the near future)
- List of publications, preferably with clickable links to each publication
- Names and contact (preferably e-mail) to two references

[1] J.-E. Rubensson et al., “Rydberg-Resolved Resonant Inelastic Soft X-Ray Scattering:
Dynamics at Core Ionization Thresholds,” Phys. Rev. Lett., vol. 114, no. 13, p. 133001,
Mar. 2015.
[2] J. Söderström et al., “Resonant inelastic x-ray scattering on CO 2  : Parity
conservation in inversion-symmetric polyatomics,” Phys. Rev. A, vol. 101, no. 6, p.
062501, Jun. 2020.
[3] S. Plogmaker et al., “HELIOS - A laboratory based on high-order harmonic generation
of extreme ultraviolet photons for time-resolved spectroscopy,” Rev. Sci. Instrum.,
vol. 86, no. 12, 2015.
[4] R. Stefanuik, R. Knut, S. Jana, J. A. Terschlüsen, A. Sandell, and J. Söderström,
“Developments and enhancements to the HELIOS pump probe system,” J. Electron
Spectros. Relat. Phenomena, vol. 224, 2018.
[5] U. B. Cappel et al., “Electronic structure dynamics in a low bandgap polymer studied
by time-resolved photoelectron spectroscopy,” Phys. Chem. Chem. Phys., vol. 18, no.
31, 2016.
[6] U. Eichmann et al., “Photon-recoil imaging: Expanding the view of nonlinear x-ray
physics.,” Science, vol. 369, no. 6511, pp. 1630–1633, Sep. 2020.