CQD Special Seminars

9. June 2026 16:30

CQD Lounge

Microscopic Structured Light-Matter Coupling for Atomic and Molecular Quantum Control

Georgios Koutentakis
Institute of Science and Technology Austria


Optical tweezers and tightly focused beams are now central tools in atomic and molecular quantum science, but many current platforms operate in regimes where plane-wave, paraxial, and point-particle approximations are no longer sufficient. In this talk, I will outline how our previous work on structured light-matter interaction provides the technical basis for a research program that treats the microscopic structure of optical fields as a genuine control resource, rather than as a hidden experimental detail.

The first part of the program focuses on atoms and molecules in realistic high-numerical-aperture tweezer fields. Longitudinal field components, polarization gradients, tensor light shifts, and spatial phase structure can generate internal-motion entanglement, decoherence, leakage, and heating. A predictive microscopic theory is therefore needed to identify dominant error channels and design mitigation strategies. For molecules, the rotational degree of freedom amplifies these effects, but also opens new possibilities for rotational control and engineered dipolar interactions. The second part applies these ideas to the trap-resolved assembly of microwave-dressed molecular complexes. Here, structured optical confinement and microwave-induced interactions define light-induced potential energy surfaces for coherent dimer and trimer formation. I will discuss how wavepacket methods, especially multilayer MCTDH, can be used to model and optimize these processes, and why Heidelberg provides an ideal environment for developing this direction.

 

up

17. Juni 2026 16:30 Uhr

Physikalisches Institut, INF 226, K 1-3

Quantum vortices in Fermi superfluids: Structure, dynamics, and dissipation

Prof. Dr. Gabriel Wlazlowski , Faculty of Physics, Warsaw University of Technology

Quantum vortices are among the most prominent examples of topological excitations in superfluids. They arise in both bosonic systems, such as superfluid helium-4 and atomic Bose–Einstein condensates, and in fermionic systems, including superfluid helium-3, metallic superconductors, and neutron matter. While topology constrains many of their properties, key aspects of vortex behavior are governed by their internal structure, which depends on quantum statistics. In this seminar, I will review recent studies of quantum vortices in Fermi superfluids and contrast them with their bosonic counterparts. Particular attention will be given to the evolution of vortex core structure across the BCS–BEC crossover, spanning the transition from weak to strong coupling. I will then discuss how these structural changes influence vortex dynamics, focusing on the emergence of vortex inertia in Fermi systems and on microscopic mechanisms responsible for dissipation in their motion. The discussion will be supported by numerical results from density functional theory for Fermi superfluids, along with comparisons with experimental results for ultracold Fermi gases.

 PreTalk: Ekaterina Vlasiuk (Institute for Theoretical Physics, Uni Heidelberg): "Enhancing superconductivity using thermal bosons"

contact
Prof. Dr. M. Weidemüller
Physikalisches Institut
Im Neuenheimer Feld 226
69120 Heidelberg
 
06221-54 19470
Ana Raspini