# Adiabatic quantum dynamics under decoherence in a controllable trapped-ion setup

## TL;DR

This paper investigates how adiabatic quantum processes behave under decoherence in a controllable trapped-ion setup, combining theoretical analysis and experimental implementation to understand robustness and optimize outcomes.

## Contribution

It provides the first combined theoretical and experimental study of adiabatic quantum dynamics under decoherence in a trapped-ion system, highlighting conditions for robustness and practical quantum algorithm execution.

## Key findings

- Decoherence can sometimes promote adiabaticity in open quantum systems.
- Optimal time windows exist for successful adiabatic quantum computation under decoherence.
- Experimental validation using a single trapped Ytterbium ion demonstrates controllable decoherence effects.

## Abstract

Suppressing undesired nonunitary effects is a major challenge in quantum computation and quantum control. In this work, by considering the adiabatic dynamics in presence of a surrounding environment, we theoretically and experimentally analyze the robustness of adiabaticity in open quantum systems. More specifically, by considering a decohering scenario, we exploit the validity conditions of the adiabatic approximation as well as its sensitiveness to the resonance situation, which typically harm adiabaticity in closed systems. As an illustration, we implement an oscillating Landau-Zener Hamiltonian, which shows that decoherence may drive the resonant system with high fidelities to the adiabatic behavior of open systems. Moreover we also implement the adiabatic quantum algorithm for the Deutsch problem, where a distinction is established between the open system adiabatic density operator and the target pure state expected in the computation process. Preferred time windows for obtaining the desired outcomes are then analyzed. We experimentally realize these systems through a single trapped Ytterbium ion $^{171}$Yb$^+$, where the ion hyperfine energy levels are used as degrees of freedom of a two-level system, with both driven field and decohering strength efficiently controllable.