Quantum interference structures in trapped ion dynamics beyond the Lamb-Dicke and rotating wave approximations

TL;DR

This paper investigates quantum interference effects in trapped ion systems beyond common approximations, revealing states with unique phase space dynamics and rapid entanglement oscillations, useful for quantum state preparation.

Contribution

It introduces a wave packet approach to analyze trapped ion dynamics without the Lamb-Dicke and rotating wave approximations, uncovering novel interference-induced states.

Findings

Existence of states with restricted phase space evolution due to quantum interference

Rapid oscillations between entangled and disentangled states

Collapse-revival dynamics with fractional revivals in key observables

Abstract

We apply wave packet methods to study an ion-trap system in the strong excitation regime imposing neither the rotating wave nor the Lamb-Dicke approximations. By this approach we show the existence of states with restricted phase space evolution, as a genuine consequence of quantum interference between wave packet fractions. A particular instance of such a state oscillates between maximal entanglement and pure disentanglement between the constitute subsystems. The characteristic crossover time is very rapid making them suitable for state preparations of EPR or Schrodinger cat states. Over longer time periods the dynamics of these states exhibits collapse-revival patterns with well resolved fractional revivals in autocorrelation, inversion and entanglement.