CQD Special Seminar

17. January 2018 14:00

Seminarraum, Institut für Theoretische Physik, Philosophenweg 19

Multiply quantised vortices in fermionic superfluids: angular momentum, unpaired fermions, and spectral asymmetry

Dr. Sergej Moroz
Technische Universität München

Quantized vortices are a hallmark of superfluids and superconductors. In this seminar I will talk about the orbital angular momentum Lz of an s-wave paired superfluid in the presence of an axisymmetric multiply quantised vortex. For vortices with winding number |k| > 1, I will argue that in the weak-pairing BCS regime, Lz is significantly reduced from its value Lz=\hbar N k/2 in the BEC regime, where N is the total number of fermions. This deviation results from the presence of unpaired fermions in the BCS ground state, which arise as a consequence of spectral flow along the vortex sub-gap states.

CQD Colloquium

29. Oktober 2025 16:30 Uhr

INF 226, K1-3 (Goldbox)

Exploring many-body physics with extended-range interactions

Dr Pascal Weckesser, Max Planck Institute of Quantum Optics

PreTalk: “Quantum droplets in Bose-Fermi mixtures”, Olivier Bleu, ITP, Heidelberg University

CQD Special Seminar

4. November 2025 14:15 Uhr

Kirchhoff-Institut für Physik, INF 227, Seminar Box 2

Josephson supercurrents and vortex dynamics in binary Bose-Einstein condensates

Dr. Alice Bellettini, Department of Applied Science and Technology, Politecnico di Torino, Italy

Quantum bosonic gases, due to their manipulability, provide the perfect platform for observing macroscopic quantum many-body phenomena. These can be for example quantum vortices (“topological defects”), being the hallmark of superfluidity, or Josephson supercurrents. Such collective effects have been recently employed in the context of quantum simulation and atomtronics. Here, I will present my research on the properties of massive quantum vortices in different configurations, and on vortex-supported supercurrents.

I will go through the inertial effects governing the massive vortex dynamics, to then focus on dipole scattering processes and on Josephson supercurrents as well as self-trapping effects in two- and many-vortex systems. Finally, I will conclude with an overview of the open questions on the topic.

contact

Prof. Dr. M. Weidemüller
Physikalisches Institut
Im Neuenheimer Feld 226
69120 Heidelberg

06221-54 19470

Ferman Alkasari