Chaotic scattering in ultracold atom-ion collisions

TL;DR

This paper demonstrates classical chaos in ultracold atom-ion collisions through numerical simulations, revealing sensitive dependence on initial conditions and potential quantum chaos signatures.

Contribution

It provides the first evidence of classical chaos in ultracold atom-ion collisions under experimentally relevant conditions and quantifies this chaos via fractal dimensions.

Findings

Chaotic dynamics depend on mass ratios and trapping frequencies.

Fractal dimension quantifies the chaos in scattering dynamics.

Chaos appears at specific energy scales in the system.

Abstract

We report on signatures of classical chaos in ultracold collisions between a trapped ion and a free atom. Using numerical simulations, we show that the scattering dynamics can be highly sensitive to initial conditions for various mass ratios and trapping frequencies, indicating the onset of chaos. We quantify this chaotic dynamics by calculating its fractal dimension. We show that for a trapped $^{88}$Sr$^+$ ion and a free $^{87}$Rb atom chaotic dynamic appears under experimentally relevant conditions, and find its characteristic energy scale. The observation of classical chaos in atom-trapped-ion collisions suggests that signatures of quantum chaos might appear, for example, through a Wigner-Dyson distribution of collisional resonances.