Nonequilibrium Spin States Studied by Neutrons

Understanding the behavior of quantum many-body spin systems far from equilibrium is a frontier challenge with broad implications for condensed matter physics, statistical mechanics, and quantum information science. Despite having far-reaching scientific and technological significance, nonequilibrium phenomena in driven-dissipative quantum systems remain largely unexplored. Unlike equilibrium macroscopic behavior, which can be described using a few state variables such as temperature and pressure, out-of-equilibrium quantum systems generally require a full quantum mechanical description—one that is often difficult to obtain due to the lack of tools capable of probing the microscopic dynamics. This project seizes a unique opportunity offered by recent development in laser pump–neutron probe techniques and accessible new advanced computational capabilities such as large-scale computation through supercomputers and quantum simulation via quantum computers to tackle out-of-equilibrium phenomena in quantum spin systems.

The goal of this research is to uncover how quantum interactions among spins govern nonequilibrium dynamics in low dimensional quantum magnets. This will be accomplished through an integrated approach that combines advanced neutron pump-probe spectroscopy, theoretical modeling, and state-of-the-art computational methods. The outcome of this research will offer insights into the roles of dimensionality, integrability, and quasiparticle interactions in governing decoherence and dynamical phase transitions in spin-based systems—providing a foundation for future quantum technologies.