Seminarium Optyczne

Ultracold atoms, since the first achievement of Bose-Einstein condensation in 1995, have proven to be an exceptionally versatile platform for studying a wide range of physical phenomena. These include nonlinear effects, superfluidity, quantized vortices, quantum magnetism, many-body correlations, localization effects, or exotic Hubbard systems, to name just a few. The rich internal structure of atoms and their sensitivity to external fields, both static and time-dependent, provide a unique opportunity to tune interatomic interactions, vary the effective dimensionality of the systems, and shape the external potentials experienced by them.In this talk, I will focus on the role of quantum fluctuations, which can stabilize ultracold systems by preventing their collapse and enabling the formation of self-bound systems known as ultradilute quantum liquid droplets. I will also describe the concept of supersolidity—systems that simultaneously exhibit properties of both superfluids and solids. Finally, novel supersolid systems, particularly those based on mixtures of ultracold bosonic and fermionic species, will be discussed.[1] Quantum Bose-Fermi Droplets, D. Rakshit, T. Karpiuk, M. Brewczyk, M. Gajda, SciPost Phys. 6, 079 (2019),[2] Self-Bound Bose-Fermi Liquids in Lower Dimensions, Debraj Rakshit et al. 2019 New J. Phys. 21 073027,[3] Supersolidity of dipolar Bose-Einstein condensates induced by coupling to fermions, M. Lewkowicz at al., arXiv:2401.05890.