Prescaling in a Far-from-Equilibrium Bose Gas.

Area of Science:

• Quantum physics
• Many-body systems
• Statistical mechanics

Background:

• Nonequilibrium quantum many-body systems evolve towards universal configurations at nonthermal fixed points.
• Reaching these fixed points typically requires very long evolution times, often beyond experimental reach.
• Early-time dynamics, or prescaling, may offer insights into universal behavior on experimentally accessible timescales.

Purpose of the Study:

• To investigate the phenomenon of prescaling in quantum many-body systems.
• To identify measurable properties that exhibit universal scaling during the prescaling regime.
• To understand the role of symmetries and conservation laws in prescaling evolution.

Main Methods:

• Theoretical analysis of spatially uniform three-dimensional Bose gases with N=3 species.
• Consideration of identical inter- and intraspecies interactions.
• Examination of symmetry breaking from U(N) to U(N-1) during evolution.

Main Results:

• Systems can exhibit prescaling, showing universal scaling in some spatial correlation properties earlier than the full fixed point.
• Prescaling evolution is governed by conservation laws linked to remaining symmetries.
• The study observed the buildup of rescaling quasicondensate distributions due to conserved transport.

Conclusions:

• Prescaling provides an avenue to study universal quantum many-body dynamics on experimentally relevant timescales.
• Symmetries and associated conservation laws play a crucial role in defining the universality class and prescaling behavior.
• The findings contribute to understanding the complex evolution of quantum systems out of equilibrium.