Quantum computing and error correction protocols for atomic quantum processors
Year: 2026
Type: dissertation
Abstract: State-of-the-art quantum computers are not yet capable of executing large-scale fault-tolerant quantum algorithms. However, experiments in recent years have demonstrated remarkable noisy intermediate-scale and early fault-tolerant quantum computations. To use the existing yet limited hardware most effectively, these protocols are typically tailored to a specific device or hardware platform that comes with certain capabilities but also with individual limitations. This thesis studies quantum protocols suited for near-term atomic quantum processors, i.e., neutral atoms in optical tweezer arrays and trapped ions. One challenge these two platforms have in common is the difficulty of performing mid-circuit measurements. On the other hand, both platforms offer advantages in qubit connectivity and scalability, both of which can be achieved by shuttling atoms or ions. Furthermore, neutral-atom and trapped-ion setups provide native support for multiqubit gates. The protocols explored in this thesis focus on quantum error correction, but also touch on quantum simulation. Concretely, we first investigate quantum autoencoders as a tool for measurement-free quantum error correction in a quantum memory. We propose an experimental implementation of this quantum machine-learning model on a shuttling-based trapped-ion quantum processor to demonstrate that quantum autoencoders can independently identify optimal strategies that combat hardware-specific noise. Secondly, we develop a software toolbox to optimize two- and multiqubit Rydberg gates utilized in neutral-atom quantum processors. We show that multiqubit gates can be useful for achieving good performance and efficient implementations of Floquet and measurement-free fault-tolerant quantum error correction with neutral atoms. Thirdly, we study the feasibility of neutral atoms as a platform for bosonic quantum error correction. We devise blueprints for encoding Gottesman-Kitaev-Preskill qubits in selected motional modes of neutral atoms confined in optical dipole traps and compare the suitability of optical tweezers and optical lattices for this purpose. Finally, we investigate a novel dissipative variational quantum eigen solver that enables the study of ground-state properties of the pure Z-2 lattice gauge theory. We demonstrate that the scheme outperforms established unitary approaches in the presence of circuit-level noise and can be implemented in available neutral-atom quantum processors. Overall, the schemes developed in this work could serve as building blocks for executing elaborate protocols on state-of-the-art atomic quantum processors. Therefore, the results of this thesis contribute to bridging the gap between the theoretical development of protocols for quantum error correction or quantum simulation and their experimental realization.
Source: RWTH Publications (RWTH Aachen)
Author: Locher, David Frederik
Institution: RWTH Aachen University
Language: English
Subfield: Artificial Intelligence
Field: Computer Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7225827186