Observing the phase space trajectory of an entangled matter wave packet

TL;DR

This paper precisely observes and analyzes the phase space trajectory of an entangled matter wave packet in a trapped ion system, revealing detailed dynamics and effects of initial temperature on entanglement.

Contribution

It provides high-precision measurement of the phase space trajectory of an entangled ion wave packet and studies the influence of initial temperature on entanglement dynamics.

Findings

Achieved better than 9% precision in phase space measurements.

Mapped phonon distributions during displacement force application.

Identified corrections to simplified system evolution models.

Abstract

We observe the phase space trajectory of an entangled wave packet of a trapped ion with high precision. The application of a spin dependent light force on a superposition of spin states allows for coherent splitting of the matter wave packet such that two distinct components in phase space emerge. We observe such motion with a precision of better than 9% of the wave packet extension in both momentum and position, corresponding to a 0.8 nm position resolution. We accurately study the effect of the initial ion temperature on the quantum entanglement dynamics. Furthermore, we map out the phonon distributions throughout the action of the displacement force. Our investigation shows corrections to simplified models of the system evolution. The precise knowledge of these dynamics may improve quantum gates for ion crystals and lead to entangled matter wave states with large displacements.