Newsroom
Stay informed with our latest news and announcements on this page. For more in-depth content, we also encourage visitors to explore our bimonthly STRUCTURES Newsletter magazine, which features a variety of articles, interviews with members, and background information on our latest research and activities.
For her research project “The formation of dormant black hole binaries: a key to mass transfer and stellar dynamics (DoBlack),” the German Research Foundation (DFG) has granted STRUCTURES Professor Michela Mapelli, astrophysicist at the Center for Astronomy of Heidelberg University (ZAH), around half a million euros.
The DoBlack project will investigate the formation of so-called dormant black holes in binary star systems – pairs where one companion is a black hole that shows no signs of mass transfer, typically detectable through X-ray emissions. These “silent” black holes have attracted increasing interest in recent years. While black holes detected with gravitational wave interferometers often represent the tip of the iceberg of the population with extreme orbital properties, dormant binaries are thought to be more representative of the black hole population in the local Universe.
To date, only a handful of such systems have been observed. However, the forthcoming fourth data release of the Gaia astrometric satellite is expected to identify several hundreds to thousands of these dormant black holes. Already, Gaia data has led to the discovery of three such systems. The orbital period of the first two of them, Gaia BH1 and BH2 (186 and 1300 days, respectively) is a puzzle for astrophysical models: too tight to be explained with a non-interacting system and too large for a binary star that evolved via unstable mass transfer.
DoBlack will address these puzzles by employing advanced numerical simulations. “DoBlack is a natural and exciting extension in understanding the formation of the new class of BH binaries,” resumes Mapelli. The goal of DoBlack is to model the formation of dormant black holes with new binary evolution models, star cluster simulations, and a comprehensive exploration of the parameter space. “We aim to reconstruct the most likely formation pathways of dormant black holes and provide a key to explain the seemingly impossible orbital period of Gaia BH1 and BH2,” says Michela Mapelli.
Michela Mapelli has led the DEMOBLACK group at the Center for Astronomy of Heidelberg University (ZAH) since July 2023 and is a member of the STRUCTURES Excellence Cluster. Her main research focus is understanding the formation of astrophysical black holes.
Further information:
STRUCTURES Professor Michela Mapelli Becomes Humboldt Scouting Sponsor for Early-Career Researchers
We are delighted to announce that Alexander von Humboldt Foundation has appointed STRUCTURES Professor Michela Mapelli, astrophysicist at the Center for Astronomy of Heidelberg University (ZAH), as a Henriette Herz Scout.
The Alexander von Humboldt Foundation's Henriette Herz Scouting Programme invites international researchers to conduct research projects in Germany. As a scout, STRUCTURES Professor Michela Mapelli now has the opportunity to identify three excellent researchers in the early stages of their careers and recommend them directly for a Humboldt Fellowship. Humboldt Scouts are selected based on their outstanding research achievements and excellence in mentoring.
Michela Mapelli has led the “Demography of Black Hole Binaries in the Era of Gravitational-Wave Astronomy” (DEMOBLACK) group at the Center for Astronomy of Heidelberg University (ZAH) since July 2023. Her main research focus is understanding the formation of astrophysical black holes.
“I am very excited to become a Humboldt Scout. My priority will be to bring to Heidelberg outstanding early-career scientists who show promise of becoming leaders in the fields of Computational Astrophysics and Gravitational-Wave Astronomy,” says Michela Mapelli. “I will focus on identifying excellent female young researchers as well as candidates from disadvantaged backgrounds and underrepresented minorities.”
The Henriette Herz Scouting Programme enables three international scientists to do research at the ZAH with a Humboldt Fellowship. Young talents as well as experienced researchers are eligible. The sponsorship period is 24 months for postdocs and 18 months for experienced researchers. Financed by the Federal Ministry of Education and Research (BMBF), the programme has opened up a new way of accessing the Humboldt Research Fellowship. The new, active scouting procedure enables successful academics in Germany to directly approach highly sought-after candidates from abroad who have so far not applied to the Foundation and invite them to conduct joint research at their institutions. In a competitive peer-review process, the Humboldt Foundation annually selects up to 40 scouts who will then themselves identify junior researchers abroad and recommend them to the Foundation. Both in terms of subject and region, the programme thus recruits new collaborative partners for Germany. It also seeks to increase the percentage of women sponsored under the Humboldt Research Fellowship Programme.
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Building a Fluid Atom by Atom: Researchers Study Emergent Hydrodynamic Behaviour of a Few-Fermion System
Macroscopic fluid dynamics is usually thought to emerge from vast numbers of microscopic particles. Now, scientists have studied fluid-like behaviour in systems of as few as ten ultracold lithium atoms.
How many particles does it take to form a fluid? A new study led by STRUCTURES researchers, published in Nature Physics, reveals that fluid-like collective behaviour can emerge with as few as ten ultracold lithium atoms. Inspired by observations in high-energy nuclear collisions, where similar phenomena are seen in systems with only a few dozen constituents, the researchers explored the onset of collectivity in quantum systems.
By precisely controlling the number of atoms and the strength of their interactions, they observed elliptic flow – a striking inversion of the initial aspect ratio that is a hallmark of hydrodynamic behaviour. This phenomenon, typically associated with much larger systems, challenges the conventional understanding that elliptic flow requires vast numbers of particles.
The study not only challenges long-held assumptions but also provides access to observables that remain elusive in high-energy nuclear collisions. This interdisciplinary effort, combining advanced experiments and theoretical modelling, paves the way for a deeper understanding of collective phenomena in quantum systems and opens exciting new avenues for research at the interface of quantum physics and particle physics.
Further information:
- Original Publication: Brandstetter, S., Lunt, P., Heintze, C. et al. Emergent interaction-driven elliptic flow of few fermionic atoms. Nat. Phys. (2025).
- News & Views: Fluids constructed atom by atom.
- STRUCTURES Blog post: The Curious Case of the World’s Smallest Fluid.
- Jochim Labs: Ultracold Quantum Gases.
Click on the image to open the newsletter as PDF. We are happy to present the 18th volume of the STRUCTURES Newsletter, featuring research news, background articles and interviews. The topics of this edition are:
- New Simulations Reveal That the Positioning of Stress
- Fibres in Cells Follows a Minimization Principle
- Lauriane Chomaz Promoted to Full Professor
- The Exploratory Projects of STRUCTURES – A Five Year Success Story
- STRUCTURES Welcomes New YAM Fellows
- Astrid Eichhorn Receives ERC Consolidator Grant
- Ruprecht-Karls Prizes for YRC Members Friederike Ihssen and Lynton Ardizzone
- YRC Member Malek Alhajkhouder Receives Rhodes Scholarship
- Recap: Schöntal Workshop 2024
The STRUCTURES Project Management Office is happy to answer questions.
Scientists at Heidelberg University have achieved a groundbreaking milestone in quantum physics: the creation of a Laughlin fractional quantum Hall state using just two ultracold fermions.
“The whole is greater than the sum of its parts” – this phrase often attributed to Aristotle captures the essence of one of the most intriguing phenomena in nature: emergence. When several parts of a physical system interact, new properties can arise that its single parts do not have on their own. A striking example is the collective behaviour of quantum many-body systems, which can produce novel effects like low-energy excitations carrying a fraction of an electron's charge.
Researchers from the group of STRUCTURES' principal investigator Prof. Selim Jochim at Heidelberg University, in collaboration with Philipp Preiss from LMU Munich, have made significant progress in understanding the emergence of fractional charges. By trapping and spinning a single pair of ultracold lithium-6 atoms in optical tweezers, they replicated the topological properties of this exotic state, previously seen only in bosonic systems. Using a tailored rotation to mimic the influence of a magnetic field, they achieved a strongly correlated atomic state described by physicist Robert Laughlin's wave function for the fractional quantum Hall effect, characterized by its collective and topological nature.
This accomplishment marks a crucial step in the study of emergence of topological phases of matter and paves the way to exploring more complex states, such as quantum Hall ferromagnetism and topological p-wave superconductors.
Further information:
- Publication 1: P. Lunt, P. Hill, J. Reiter, P. M. Preiss, M. Gałka, S. Jochim, Phys. Rev. Lett. 133, 253401 (2024)
- Publication 2: P. Lunt, P. Hill, J. Reiter, P: M. Preiss, M. Gałka, S. Jochim, Phys. Rev. A 110, 063315 (2024)
- APS Physics Viewpoint Article: Ultracold Fermions Enter the Fractional Quantum Hall Arena
- Selim Jochim's group
We are delighted to announce that STRUCTURES Professor Astrid Eichhorn has secured one of the prestigious ERC Consolidator Grants by the European Research Council (ERC). This highly competitive grant will support her pioneering research into the quantum nature of gravity, enabling her and her team to deepen our understanding of this fundamental aspect of the universe. Over a period of five years, her project will receive two million euros in funding.
Astrid Eichhorn's research focuses on the quantum properties of space-time and the interplay with the fundamental building blocks of the universe, including elementary particles of the Standard Model of particle physics, dark matter and dark energy. In her ERC-funded project “Probing the Quantum Nature of Gravity at All Scales” (ProbeQG) she aims to primarily explore how to test fundamental theories on the quantum structure of space-time through experiments and observations. The central challenge is that the quantum properties of space-time manifest on tiny length scales – about 17 orders of magnitude below the scales that can be directly examined experimentally by the Large Hadron Collider, the particle accelerator of the European research center CERN. The main idea of the ProbeQG project is to identify “lever arms”. These are systems that translate the effects of quantum gravity on tiny scales into effects that are experimentally accessible. To this end, Prof. Eichhorn and her team want to build a bridge between the theory of asymptotically safe quantum gravity, particle physics, black hole physics and cosmology.
Astrid Eichhorn is a STRUCTURES Professor at the Institute of Theoretical Physics (ITP), where she is heading the Quantum Gravity group. She completed her PhD at the University of Jena, before she pursued a postdoctoral position at Perimeter Institute for Theoretical Physics in Waterloo, and subsequently became a research fellow at Imperial College London. At Heidelberg University she led an Emmy Noether Group on the fundamental quantum structure of space-time and matter from 2016 to 2020. From 2019 she served first as associate professor and from 2023 as full professor at the Centre for Cosmology and Particle Physics Phenomenology at the University of Southern Denmark. In 2024, she returned to Heidelberg, where she was appointed to one of the newly established STRUCTURES Professorships. Prof. Eichhorn's contributions to quantum gravity have earned her recognition as a leading voice in the field.
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We are delighted to congratulate our member Dominika Wylezalek, research group leader at the Centre for Astronomy (ZAH) of Heidelberg University, on winning one of the three Klaus-Georg and Sigrid Hengstberger Awards for early-career scientists.
Since 2004, the Klaus-Georg and Sigrid Hengstberger Prize has been awarded annually to excellent early-career scientists at Ruperto Carola. The award comes with a prize money of €12,500 and enables the prizewinners to hold a scientific symposium at the International Academic Forum Heidelberg (IWH).
The symposium led by astrophysicist Dominika Wylezalek will focus on the formation and evolution of galaxies – complex phenomena shaped by intricate interactions between stars, gas, dust, black holes, and supernovae. The symposium, titled “Quo Vadis Galaxy Evolution: How Galaxies Form and Evolve,” is scheduled for June 2025.
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