Quantum driving protocols for a two level system: from generalized Landau-Zener sweeps to superadiabatic control

TL;DR

This paper experimentally compares various quantum driving protocols, including Landau-Zener and superadiabatic methods, for preparing high-fidelity states in two-level systems, analyzing their speed and robustness.

Contribution

It provides experimental validation of different driving protocols for two-level quantum systems, highlighting their efficiency and robustness under realistic conditions.

Findings

Superadiabatic protocols achieve perfect state following.

Minimum time for high-fidelity state preparation is characterized.

Robustness varies among protocols under parameter uncertainties.

Abstract

We present experimental results on the preparation of a desired quantum state in a two-level system with the maximum possible fidelity using driving protocols ranging from generalizations of the linear Landau-Zener protocol to transitionless driving protocols that ensure perfect following of the instantaneous adiabatic ground state. We also study the minimum time needed to achieve a target fidelity and explore and compare the robustness of some of the protocols against parameter variations simulating a possible experimental uncertainty. In our experiments, we realize a two-level model system using Bose-Einstein condensates inside optical lattices, but the results of our investigation should hold for any quantum system that can be approximated by a two-level system.