News Overview

We are happy to present the tenth volume of the STRUC­TURES Newsletter with the following topics:

1. STRUC­TURES Short News
2. ERC Synergy Project: Dynamics & Control of Neural Stem Cells
3. YRC: New Speakers & Upcoming Activities
4. Simulations of Planetesimal Formation Reproduce Key Properties of Asteroids, Comets
5. Annalisa Pillepich Re­ceives ERC Consolidator Grant

The STRUC­TURES Project Management Office is happy to answer questions and to receive feedback.

STRUC­TURES theo­re­ti­cal physicists from the group of Richard Schmidt ( STRUC­TURESInstitute for Theo­re­ti­cal Physics) at Hei­del­berg Uni­ver­si­ty together with experimentalists from the Max Planck Institute of Quan­tum Optics in Garching have made a major breakthrough in the study of atomic Bose-Fermi mixtures. These mixtures are ultracold atomic systems that are composed of both bosonic and fermionic particles and thus enable unique interactions forming new phases of matter. In their study, published in Nature Physics, the re­search team observed first evidence for a quan­tum phase transition from a so-called polaronic to a molecular phase in a density-matched degenerate Bose-Fermi mixture.

This transition, which occurs at low temperatures, is induced by interactions depleting the fraction of bosons that occupy the lowest energy state, and by the build-up of strong correlations. Both result in the emergence of a molecular Fermi gas, which has been theoretically modelled within the group of Prof. Schmidt together with Jonas von Milczewski. The features of the underlying quan­tum phase transition represent a new phenomenon, complementary to the paradigmatic Bose-Einstein condensate/Bardeen–Cooper–Schrieffer crossover observed in Fermi systems. By driving the system through the transition in an experiment by the group of Immanuel Bloch and Xin-Yu Luo in Munich, the researchers have used this novel quan­tum phase transition to produce a record-large sample of sodium-potassium molecules in their absolute ground state exhibiting a large molecule-frame dipole moment in the quantum-degenerate regime.

Further Information and Links:

• Original Publication in Nature Physics: Duda, M., Chen, XY., Schindewolf, A. et al., Nat. Phys. (2023)
• Re­search Briefing: Using a quan­tum phase transition to efficiently produce heteronuclear molecules
• Quan­tum Matter Theory Group - Richard Schmidt

We are happy to announce this week's Jour Fixe with a talk “Women in STEM” by Prof. Christiane Schwieren, Equal Opportunities Commissioner at Hei­del­berg Uni­ver­si­ty and expert in Behavioural and Experimental Economics at Alfred-Weber-Institute for Economics. As usual, the Jour Fixe will take place on Friday, February 10, 2023 at 1:30 pm. You are welcome to join the meeting either in person or via Zoom.

Abstract: All STEM fields in German universities suffer from a difficulty in recruiting and retaining qualified women – starting at the student level, but getting worse the higher up in the academic hierarchy we look. Re­search on gender differences in preferences, using both experimental methods and analyses of panel data, can shed some light on the mechanisms leading to this. There is also evidence available on the success of certain policies that have been implemented to recruit more women for STEM careers. Behavioral economics is well suited to suggest evidence-based interventions for the case that the current situation does not reflect preferences well. Libertarian paternalist or “nudging” interventions have been successfully used in a diversity of settings to counter especially (unconsciously) discriminatory hiring practices. However, we are everywhere still far from gender equality, which leads to the question what factors have been overlooked or not tackled sufficiently so far. Among them are both the negative effects of being in a “token” position as a women on women, but also male reactions to increasing gender equality. Identity economics offers insights into these aspects and can help to develop new, structural solutions.