University of Connecticut Perturbative Theory Predicts Plateau Height & Timescale

A perturbative theory developed by C. L. Sriram and Lea F. Santos at the University of Connecticut, and Soumya Kanti Pal at the Tata Institute of Fundamental Research, now provides analytical expressions for both the height and timescale of how long it takes for strongly interacting quantum systems to approach equilibrium, a calculation previously beyond reach. Researchers found that nearly conserved quantities fragment the system’s quantum behavior, leading to a two-stage equilibration process with long-lived prethermal plateaus. Unlike conventional eigenstate thermalization hypothesis, the team’s fragmented eigenstate thermalization hypothesis (fETH) obeys a symmetry-imposed selection rule that restricts which system sizes can be compared. This band-resolved…