CQD Special Seminar

10. April 2017 13:00

Konferenzraum 4, Physikalisches Institut, INF 226

Visible Efimov effect in the spectroscopy of Bose polarons

Associate Professor Xiaoling Cui
Institute of Physics, Chinese Academy of Sciences, Beijing, China

Bose polaron is generally believed as a promising many-body system to host the novel Efimov correlations. Nevertheless, no signature of Efimov physics has been reported in the existing Bose polaron experiments up to date. In this talk, I will show that the Efimov physics can be directly observed in the spectroscopy measurement of Bose polarons with large mass imbalance. Taking the ⁶Li(impurity)- ¹³³Cs(bosons) system as an example, our calculation shows two visible Efimov branches in the spectral response of ⁶Li atoms, as well as the spectral broadening due to their hybridizations with the attractive polaron branch. These results suggest that the highly mass-imbalanced atomic mixtures can serve as an ideal platform for the observation of intriguing few-body correlations in a many-body environment.

CQD Colloquium

12. November 2025 16:30 Uhr

INF 226, K1-3 (Goldbox)

tba

Dr Rob Smith, University of Oxford

PreTalk: Andreea Oros, KIP, Heidelberg University

CQD Special Seminar

7. November 2025 13:30 Uhr

INF 226, K1-3 (Goldbox)

Scale invariance and universal probability distribution of an order parameter across a continuous phase transition

Prof David Clément , Institut d'Optique Graduate School, Laboratoire Charles Fabry, France

Scale invariance lies at the foundation of modern statistical physics and underpins the description of continuous phase transitions. Its most striking manifestation is the universal probability distribution function (PDF) of the order parameter, which encapsulates the complete statistical structure of critical fluctuations—beyond what traditional quantities such as averages or critical exponents can reveal. However, this universal distribution is exceptionally challenging to measure, as it reflects the non-Gaussian and scale-invariant nature of critical fluctuations.

We will report on the experimental study of the statistics of the condensate order parameter across the superfluid–Mott transition in a gas of 3D lattice bosons, making use of single-atom-resolved detection in momentum space [1]. First, we observe non-Gaussian statistics of the order parameter near the transition, distinguished by non-zero and oscillating high-order cumulants [2]. We provide direct experimental evidence that these oscillations are universal. Second, crossing the Mott transition for various entropies and collapsing the cumulant oscillations, we obtain the non-universal coefficients required to reconstruct the universal PDF [3]. Finally, this universal scaling function determined experimentally is shown to yield algebraic scaling laws whose exponents are consistent with the critical exponents of the (expected) 3D XY universality class.

contact

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

06221-54 19470

Ferman Alkasari