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Formation of quasiparticles in ultracold quantum gases.

PhD defence, Wednesday, 12th May 2021. Magnus Graf Skou.

2021.05.12 | Karen Konradi

Magnus Graf Skou

Quasiparticles are deeply fascinating to study since they may consist of numerous particles and their excitations. The polaron is a prominent example of such a quasiparticle and describes the scenario of an impurity interacting with a surrounding medium. Since the polaron is important for many novel technologies, investigating the exotic quasiparticle in well-controlled environments is therefore highly desirable.

During his Ph.D. studies, Magnus Graf Skou has studied impurity dynamics in ultracold atomic gases. In particular, a Bose-Einstein condensate was used as a medium and impurity physics was explored using another quantum state of the atoms. Importantly, a transition from initial dynamics to the eventual formation of the polaron was resolved. Furthermore, interactions between polarons, leading to the emergence of bipolarons, were observed for the first time. The results therefore consolidate the current understanding of the quasiparticles and pave the way for further exciting research of quantum impurities and their interactions.

The PhD study was completed at Department of Physics and Astronomy, Faculty of Natural Sciences, Aarhus University.

This summary was prepared by the PhD student.

Time: Wednesday, 12th May 2021 at 10.00 am.
Place: The PhD defence will be held online. To receive a link to the event, please send an e-mail to Jan Arlt, arlt@phys.au.dk.
Title of PhD thesis: Quantum impurity dynamics and formation of polarons and bipolarons in Bose-Einstein condensates.

Contact information: Magnus Graf Skou, e-mail: magnus.skou@phys.au.dk, tel.: +45 28155683

Members of the assessment committee:

Lektor Pietro A. Massignan, Universitat Politècnica de Catalunya Barcelona, Spain

Professor Rudolf Grimm, Innsbruck University, Austria

Lektor Alberto Imparato (chairman), Department of Physics and Astronomy, Aarhus University, Denmark

Main supervisor:
Associate Professor Jan Joachim Arlt, Department of Physics and Astronomy, Aarhus University, Denmark

Language: The PhD dissertation will be defended in English

The defence is public.
Due to the coronavirus situation, the PhD thesis will not be available for reading at the offices of the PhD administration. Instead, interested parties may send an e-mail to gradschool.nat@au.dk to receive a digital copy of the PhD thesis. Please note, it may in certain cases be necessary to make an individual arrangement to read the PhD thesis.

PhD defence
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