Emergent prethermalization signatures in out-of-time ordered correlations

Understand

How a many-body quantum system thermalizes --or fails to do so-- under its own interaction is a fundamental yet elusive concept.

• Here we demonstrate nuclear magnetic resonance observation of the emergence of prethermalization by measuring out-of-time ordered correlations.
• We exploit Hamiltonian engineering techniques to tune the strength of spin-spin interactions and of a transverse magnetic field in a spin chain system, as well as to invert the Hamiltonian sign to reveal out-of-time ordered correlations.
• At large fields, we observe an emergent conserved quantity due to prethermalization, which can be revealed by an early saturation of correlations.