Fractional quantum Hall (FQH) states are paradigmatic examples of strongly correlated topological quantum matter, combining geometric order and strong interparticle interactions. Yet, limited microscopic control in solid-state platforms often restricts observations to global current or spectroscopy probes. Engineered quantum systems, such as ultracold atoms in optical lattices, offer a complementary route for exploring topological order leveraging precise control over Hamiltonian parameters and access to local observables through quantum gas microscopy. The primary goal of this project is to prepare and probe quantum-engineered fermionic FQH states for the first time in a next-generation quantum gas microscope. First, we will implement direct laser cooling of fermionic Li-6 atoms to efficiently prepare individual atoms in the ground state of optical tweezers, and holographically project lattice potentials to assemble Fermi-Hubbard systems atom by atom. To explore FQH physics, we will implement small fermionic Harper-Hofstadter systems via Floquet engineering. Leveraging our system’s excellent coherence, we will extend observations beyond two particles and perform first observations fractionally charged quasi-hole excitations pinned by local repulsive potentials. To access a broader class of fermionic FQH states, we will build upon recent advances in multi-orbital lattices and engineer p-wave interactions between pairs of spinless fermions. This approach will facilitate first microscopic studies of exotic Pfaffian states. Our results will significantly impact research in quantum simulation and topological physics. Technically, we will advance programmable optical lattices, enabling sub-second cycle times and unprecedented levels of control in quantum gas microscopes. Implementing p-wave interactions will facilitate the exploration of Pfaffian states and non-Abelian excitations, which are building blocks for fault-tolerant topological quantum computing.

How the organs of a developing organism achieve their correct size and shape is a fundamental unresolved question in biology. Mammalian embryos possess a remarkable ability to regulate (restore) the correct size of their tissues and organs upon perturbations during early development, yet how this is achieved is unknown. Addressing this question has so far been challenging because it requires a multiscale approach that integrates precise measurements with theoretical frameworks. We are now in an excellent position to unravel the mechanisms by which the mouse spinal cord regulates its size and shape during development by building on our experience with quantitative studies in this system. We previously obtained quantitative spatiotemporal data of growth, pattern and morphogen signalling dynamics in the spinal cord. We showed that there is a critical period during which morphogen signaling is interpreted to specify cell fates, uncovered a mechanism that allows precise pattern formation, and identified a link between the growth rate and tissue anisotropy. Our expertise now enables us to address the following new questions: 1) how is size regulation in the spinal cord achieved at the tissue and cellular level; 2) what is the molecular mechanism of size regulation, in particular the role of morphogen signaling; 3) how is the regulation of spinal cord size linked to the regulation of its shape. To address these questions, we will combine precisely controlled ex vivo assays in organoids and whole embryo culture, and in vivo advanced mouse genetics and mosaic analysis. We will obtain highly resolved dynamic data and interpret it in the context of rigorous theoretical frameworks. The project will advance our understanding of the fundamental mechanisms of tissue size control and the constraints they impose in regeneration and disease. Our results will have implications for in vitro tissue engineering and research on multi-organ coordination and robustness during development.

ISTplus offers two-year fellowships for highly qualified, incoming postdocs fulfilling the mobility criterion, who will have the chance to join our world-class research teams in the fields of Biology, Neuroscience, Mathematics, Physics, and Computer science at IST Austria. The fellows will be integrated in a truly interdisciplinary research environment, interacting closely with colleagues from different fields (through shared facilities, joint projects, and events). The international dimension will be ensured by the multinational teams (with employees from more than 50 countries) and through international networking. An open, bottom-up international recruiting process will ensure scientific quality and potential of the selected ISTplus fellows. Already at the beginning of their stay, fellows together with a Career Counselor will assess their professional profile and skill set, define the direction of their future career path (be it academic or non-academic) and elaborate a development plan, supported by our Targeted Competence Building Program. A co-supervision scheme will support the fellows during their stay, meant to oversee scientific progress, but also to give advice regards individual career planning. A secondment scheme should kick-start and facilitate cross-boundary networking and translational research with an intersectorial network of excellent partners, incl. SMEs, applied research companies, organizations in the field of tech transfer and science education, and commercial enterprises. Fellows will be supported in the choice of the right partner, in setting up a research plan, and may opt for an extension of the fellowship for up to six months to enable intersectoral mobility. Various events, workshops, trainings, and further activities in the area of tech transfer will cultivate an open-minded entrepreneurial spirit among program participants.

Cell motility is driven by a complex network of force-generating biological machinery. The key component in this machinery is the dynamic network of filamentous actin (F-actin) and actin binding proteins (ABPs) which maintain and regulate the network. However, structural information for many ABP-actin complexes, as well as their in situ spatial distribution remain elusive. This is because ABPs cannot be easily studied in isolation, often exhibiting structural stability only when embedded in a complex filamentous network found within cells. This has hindered a complete understanding of actin network regulation in cell migration. Addressing this important question requires understanding exactly how ABPs select F-actin, and conversely how F-actin geometry recruits specific ABPs. Cryo-electron tomography (cryo-ET) can reveal both cellular ultrastructure and molecular details, but often is lower resolution than a single particle cryo-EM approach. Thus, innovative methods remain key to drive advancement in understanding in situ structures. In this fellowship I will combine my expertise of single particle cryo-electron microscopy with expertise of cryo-ET in the Schur lab to develop a novel hybrid single particle cryo-ET approach in order to reveal high-resolution structures and contextual information of ABPs bound to F-actin directly within cellular protrusions. ISTA is the ideal research institute due to abundant access to high-end electron microscopes necessary for methods development. The outcome of this action are tools for high resolution in situ structure determination and a better understanding of cell migration, a process deeply rooted in malignant metastasis. Results will be disseminated through key research conferences and high-impact open-access publications. Communication activities will be achieved through 3D rendered visual scientific illustrations targeting social media platforms and institute-organized public outreach events.

Embryogenesis is achieved by the close interplay between the gene regulatory networks that control cell fate specification and the physical processes by which the embryo takes shape. While each of these systems has been extensively investigated over the past decades, comparably little is yet known about how they functionally interact across different scales of organization within the physiological context of the developing embryo. The central aim of this proposal is to elucidate the fundamental principles underlying the interaction and feedback between cell mechanics and fate specification during vertebrate gastrulation. Using zebrafish as a vertebrate model organism, we will explore how germ layer progenitor cell fate specification affects the physical processes by which the gastrula takes shape, and, vice versa, how alterations in cell/tissue mechanics feed back onto the gene regulatory networks and signals controlling progenitor cell fate specification during gastrulation. To dissect the fundamental mechanisms underlying this crosstalk, we will combine genetic, cell biological and biophysical experimentation with mathematical modeling. We expect that this transdisciplinary approach will provide answers to a central yet unresolved question in developmental biology: how the interplay between cell mechanics, dynamics and fate specification drives embryo morphogenesis and patterning.