Out-of-Time-Order-Correlator for van der Waals potential

TL;DR

This paper investigates the behavior of the out-of-time-order correlator (OTOC) in diatomic molecules, revealing exponential growth near dissociation energy linked to classical turning points, aiding understanding of chaos in molecular dynamics.

Contribution

It demonstrates that OTOC can grow exponentially in realistic molecular potentials, connecting quantum chaos indicators to classical atomic motion at turning points.

Findings

OTOC exhibits exponential growth near dissociation energy

Growth is linked to classical dynamics at the turning point

Results help interpret chaos in complex molecules

Abstract

The quantum-to-classical correspondence is often quantified in dynamics by a quantity referred to as the out-of-time-order correlator (OTOC). In chaotic systems, the OTOC is expected to grow exponentially at early time, characteristic of a Lyapunov exponent, however, exponential growth can also occur for integrable systems. Here we investigate the OTOC for realistic diatomic molecular potentials in one degree of freedom, finding that the OTOC can grow exponentially near the dissociation energy of the moelcule. Further, this dynamics is tied to the classical dynamics of the atoms at the outer classical turning point of the potential. These results should serve to guide and interpret dynamical chaos in more complex molecules.