Absorbing state phase transitions in long-range interacting quantum spin systems

• Applicants: Professor Dr. Igor Lesanovsky; Professor Dr. Christian Lubich
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas ; Mathematics ; Theoretical Condensed Matter Physics
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 465199066

Understanding the dynamics of open many-body quantum systems with long-range interactions is one of the most challenging tasks in physics. This concerns their real time evolution as well as the analysis of their stationary state. Advances in tackling this problem are currently much sought after and breakthroughs here will impact directly on recent state-of-the-art research across several physical domains, ranging from condensed matter physics to quantum optics. The goal of this project is to develop, advance and apply numerical and analytical approaches for the analysis of dissipative many-body quantum systems that feature long-range interactions together with absorbing states. These settings represent paradigmatic instances of nonequilibrium physics and are anticipated to display novel phenomena, such as critical behaviour lying outside that of known equilibrium universality classes. To achieve these ambitious goals, our research team gathers experts from numerical analysis and many-body quantum theory. The work programme is designed such that it strongly integrates the development and benchmarking of numerical and analytical techniques in the context of timely research problems, ranging from absorbing-state phase transitions to quantum generalisations of reaction-diffusion problems. Combining state-of-the-art tensor networks, perturbative analytical approaches and exact analytical calculations will enable the study of critical phenomena in various dimensions and permits a systematic investigation of temporal correlations. Our research programme promises to advance the state-of-the-art of numerical and analytical methods for open quantum systems and may allow to shed light on current open questions in the domain of nonequilibrium physics, potentially enabling us to uncover new forms of universal behaviour and new nonequilibrium phases of open many-body quantum systems.

• DFG Programme: Research Units
• Subproject of: FOR 5413: Long-range interacting Quantum Spin systems out of equilibrium: Experiment, Theory and Mathematics
• International Connection: Austria, Hungary, United Kingdom
• Cooperation Partners: Dr. Gianluca Ceruti; Professor Dr. Juan P. Garrahan; Professor Dr. Örs Legeza
• Co-Investigator: Dr. Dominik Sulz