CQD Special Seminar

7. April 2022 11:15

KIP, HS 2

Tunable interactions in driven two-component Bose-Einstein condensates: effective three-body interactions and beyond-mean-field effects

Dr. Lucas Lavoine
Institut d'Optique, Paris

Mixtures of Bose-Einstein condensate offer situations where the usual mean-field interaction is reduced and higher-order terms may play a dominant role in the equation of state. In this context, the case of coherently coupled two component Bose-Einstein condensate will be addressed. First, we demonstrate a method to engineer large attractive three body interactions with striking consequences on the system properties [1]. Second, we measure the beyond-mean field equation of state and show that it is modified as compared to the uncoupled case [2].

[1] A. Hammond, L. Lavoine, and T. Bourdel, ‘’Tunable three-body interactions in driven two-component Bose-Einstein condensates’’, Phys. Rev. Lett. 128, 083401
[2] L. Lavoine, A. Hammond, A. Recati, D. S. Petrov, and T. Bourdel, ‘’Beyond-Mean-Field Effects in Rabi-Coupled Two-Component Bose-Einstein Condensate ‘’, Phys. Rev. Lett. 127, 203402, 2021

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