SFB 1432:  Fluctuations and Nonlinearities in Classical and Quantum Matter beyond Equilibrium

Subject Area Physics
Chemistry
Mathematics
Term since 2021
Project identifier Deutsche Forschungsgemeinschaft (DFG) - Project number 425217212
 

Project Description

The properties of physical systems are often approximated by assuming local equilibrium and linear response. In situations where such approximations do not apply, however, novel, and partially surprising phenomena arise, in particular on short time and length scales. The scope of the CRC 1432 is to study how the behaviours of classical and quantum-mechanical systems is modified by fluctuations being far from equilibrium or dominated by strongly nonlinear interactions. Based on recent developments in experiment, simulations, and theory, we directly explore the statistical properties of physical quantities, concentrating especially on advanced aspects such as non-Gaussian statistics, extreme nonlinearities, quantum fluctuations, quantum entanglement, and non-Markovian dynamics with a time-delayed response. In all these cases, fluctuations can lead to new and intriguing physical phenomena, novel functionalities and even applications. A key element of this CRC is the use of a wide range of systems and methodological approaches from classical and quantum physics. This general approach allows us to identify the general impact of nonequilibrium fluctuations and nonlinear couplings in the fields of soft matter, quantum transport, spintronics, nanomechanics, and ultrafast phenomena. By exposing driven systems to strongly coupled and non-trivial classical and quantum-mechanical fluctuating environments, we will be able to provide well-controlled nonequilibrium surroundings and thus to enter mainly unexplored territory. In addition to novel complex collective processes such as dynamical phase transitions or switching phenomena, we also expect a better understanding of the quantum-to-classical transition for fluctuations in nonequilibrium situations, for which no generally accepted criteria exist. Extreme nonlinearities in well-characterized systems will open novel opportunities to investigate the dynamics, e.g., in atomic and nanomechanical systems. We study this interplay between fluctuations and nonlinearities in out-of-equilibrium situations in a broad spectrum of hybrid systems combining charges and fields, as well as collective excitations based on spin and motional degrees of freedom. We combine the expertise and methods from experimental and theoretical physics with chemistry and mathematics. In the first funding period, we have created innovative tools and experimental approaches to characterize nonequilibrium fluctuations and nonlinearities which have allowed for detailed insights into their influence on classical and quantum-mechanical systems. In the future, advancing these concepts to valuable tools for discovery, we will allow the CRC to enter new and unexplored areas of science.
DFG Programme Collaborative Research Centres
International Connection Israel

Current projects

Completed projects

Applicant Institution Universität Konstanz
Participating University Georg-August-Universität Göttingen; Technische Universität München (TUM)
Spokesperson Professor Dr. Wolfgang Belzig