【Date and Time】5-June-2025 1:30pm (Beijing time)

【Venue】Room 526

【Host】Wei Zhang (Renmin University of China & BAQIS)

【Title】Localization and Anyonization of strongly interacting 1D Bose gases

【Speaker】 

Hanns-Christoph Nagerl, a full professor for experimental physics at the University of Innsbruck, studied physics in Gottingen, San Diego, and Innsbruck and completed his doctoral thesis in 1998 on the subject of “Ion Strings for Quantum Computation” with Prof. R. Blatt. As a postdoctoral researcher he worked at the California Institute of Technology (Caltech) with Prof. J. Kimble on single ultracold neutral atoms for quantum information purposes. In 2000 he joined Prof. R. Grimm in Innsbruck to set up an ultracold-atom group and to work on atomic and molecular quantum gases and matter waves. He received his “habilitation” in 2006, with this became associate professor, and then advanced to full professor for experimental physics at the University of Innsbruck in 2011. Professor Nagerl has been awarded numerous prizes, e.g. a START prize grant (2003), the Rudolf-Kaiser prize (2010), an ERC-Consolidator prize grant (2011), the prestigious Wittgenstein award (2017), and an ERC-Advanced prize grant (2018). Presently, he is the director of the Institute for Experimental Physics of the University of Innsbruck. His scientific interests center on quantum many-body physics and quantum simulation on the basis of ultracold atoms and molecules.

【Abstract】

In this talk, I will report on two sets of experiments.  In the first, starting from 2-nK samples in a compensated flat-bottom optical trap, we observe many-body dynamical localization in a 1D quantum under quantum kicked rotor (QKR) setting [1] as the interactions are tuned from zero into the Tonks-Girardeau (TG) regime. After some initial evolution, the momentum distribution freezes and retains its characteristic structure as the sample is kicked periodically hundreds of times. In contrast, for random kicking, the distribution becomes uniform and loses all structure.

In the second set of experiments, we study impurity transport for strongly interacting impurity atoms through fermionized bosons. We measure the momentum relaxation time as we vary the initial momentum and the interaction strength for abruptly “injected” impurities. For adiabatic following of the ground state we find that smoothly moving impurities develop anyonic properties [2]. We have observed that the momentum distribution of impurities changes from bosonic to fermionic, as the mean momentum varies from zero to Fermi momentum for the fermionized gas.

[1] Observation of many-body dynamical localization, Y. Guo et al., arXiv:2312.13880 (2023)

[2] Observing anyonization of bosons in a quantum gas, S. Dhar et al.,

Nature (2025)