DFG Research Unit FOR 5413

Prof. Dr. Beatriz Olmos Sanchez

This project explores how long-range interactions reshape topological phases in quantum spin systems. It investigates protected edge excitations, dynamical signatures of topology, and novel Floquet and dissipative phases using analytical and numerical methods. A central goal is to translate these theoretical predictions into measurable observables for experimental platforms, particularly Rydberg atom arrays.

PD Dr. Björn Sbierski

This project develops a Keldysh-diagrammatic approach for quantitatively simulating the non-equilibrium dynamics of interacting quantum spin systems beyond one dimension. The method will cover different spin models, lattice geometries, driving protocols, and correlation functions, with a particular focus on long-range interactions. Applications will be benchmarked against numerical calculations and experiments with cavity and Rydberg systems.

Prof. Dr. Marius Lemm and Prof. Dr. Stefan Teufel

This project investigates how rapidly quantum information can propagate in systems with long-range interactions. It develops rigorous bounds that account for time-independent interactions, the specific structure of Rydberg Hamiltonians, disorder, and decoherence. In collaboration with P05, the project will also design experimentally realistic protocols for observing super-ballistic information transport in two-dimensional Rydberg systems.

Prof. Dr. Sebastian Slama and Prof. Dr. Beatriz Olmos Sanchez

This project combines individually controlled Rydberg atoms with a high-finesse optical cavity to study the interplay of direct long-range and cavity-mediated all-to-all interactions. The platform will enable the creation and detection of extended collective Rydberg states and the investigation of cavity-mediated nonlocal facilitation. It will also be used to realize a cavity-mediated XY spin model for quantum simulation and long-range quantum-state transfer.

Prof. Dr. Joszef Fortagh and Dr. David Petrosyan (Mercator fellow)

This project aims to achieve strong, coherent coupling between individually trapped Rydberg atoms and a superconducting microwave resonator. The cavity will mediate controllable interactions between spatially separated atoms, enabling excitation exchange, entanglement, and quantum-state transfer over macroscopic distances. Extending the system to several atoms will provide a platform for studying all-to-all interacting few-body systems and implementing multi-qubit operations.

Prof. Dr. Igor Lesanovsky and Prof. Dr. Christian Lubich and Dr. Federico Carollo (Mercator Fellow)

This project studies non-equilibrium phases and absorbing-state transitions in open quantum systems with long-range interactions. It develops faster and more flexible tensor-network algorithms for simulations in one and two dimensions, supported by analytical hydrodynamic and mean-field approaches. The project will also investigate multi-time correlations, correlation spreading, emission spectra, and relaxation towards stationary states.

Prof. Dr. Daniel Braun and Andreas Günther, and Dr. David Petrosyan (Mercator fellow)

This project investigates how long-range correlations and spatial order emerge in disordered, strongly interacting Rydberg spin systems. Using dynamically tunable van der Waals and dipole-dipole interactions together with spatially resolved ion microscopy, we will study the formation of Rydberg crystalline states in quasi-one-dimensional atomic ensembles. We will also explore effective ultra-long-range interactions mediated by correlated quantum matter and extend the grabit approach to simulate disordered, open spin systems with long-range interactions.

Prof. Dr. Christian Groß

This project investigates many-body dynamics and information transport in two-dimensional quantum magnets realized on a Rydberg-atom platform with dipolar XY interactions. We will study edge-localized dynamics in weak 2D topological insulators and test its stability in the interacting many-body regime. Time-reversal protocols and out-of-time-order correlation measurements will provide additional probes of information spreading. A further goal is to identify tailored initial states that enable enhanced quantum transport and fast state transfer in long-range interacting systems.