• Nuclear, Particle, Astroparticle and Cosmology (NUPAC) Seminars

September 15, 2026 2:00 PM
PAIS 3205

Host:

Huaiyu Duan

Presenter:

Ramya Bhaskar (Sandia)

Many-body neutrino systems in core-collapse supernovae (CCSN) environments are densely coupled systems of many particles, with neutrino self-interactions dominating the region between the proto-neutron star core surface and the outer layers of the CCSN where neutrinos interact with matter. Neutrino systems in the self-interaction region are often approximated as a spin 1/2 random Heisenberg system, a system also used as a proxy for spin glasses. Unlike other models often explored as many-body neutrino systems in CCSNs, this particular model is notoriously difficult to simulate at long times and large particle number N. Consistent accurate extraction of multi-point correlation functions at later times becomes difficult as N grows, both numerically on classical devices and experimentally on quantum hardware. We numerically investigate the behavior of out-of-time-ordered correlators (OTOCs), a multi-point correlation function often used as a measure of quantum scrambling (how quantum information spreads throughout a system). We also consider alternative witnesses for the OTOC. One alternative witness examined is the Dynamical Quantum Phase Transition (DQPT)--an observable defined as the wave function overlap between the initial and final states of a system, which is computationally cheaper to extract from classical and quantum platforms. We consider the DQPT-OTOC relationship in future explorations of computationally cheaper, alternative proxy measures of quantum information scrambling, signatures of prethermalization and other ETH-related phenomena in densely coupled neutrino systems.

This work was supported in part by Sandia National Laboratories (SNL), and the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, DOE (NP) Award DE-SC0020970, the University of Washington's Office of Graduate Student Equity & Excellence and Department of Physics. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.