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Trapped-Ion Qudit Quantum Computing: Due-Diligence Assessment of the Ringbauer Program

Rowan Brad Quni-Gudzinas

Published Aug 10, 2026• 0 citations
Publisher

Abstract

Due-diligence research note assessing the trapped-ion qudit quantum computing program led by Martin Ringbauer at the University of Innsbruck. Covers the universal qudit processor (Nature Physics 2022), the native qudit entanglement gate based on a generalized light-shift mechanism (Nature Communications 2023), and the lattice gauge theory simulation with ion qudits (PRX Quantum 2024). All bibliographic metadata and experimental figures were verified against live Crossref records and the published article body. Records measured light-shift gate fidelities 99.6(1)%, 98.7(2)%, 97.0(3)%, 93.7(3)% for dimensions 2-5, the quadratic error scaling with dimension, and maximal Schmidt-number entanglement certification up to d=5.

DOI
10.5281/zenodo.21879121

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Due-diligence research note assessing the trapped-ion qudit quantum computing program led by Martin Ringbauer at the University of Innsbruck. Covers the universal qudit processor (Nature Physics 2022), the native qudit entanglement gate based on a generalized light-shift mechanism (Nature Communications 2023), and the lattice gauge theory simulation with ion qudits (PRX Quantum 2024). All bibliographic metadata and experimental figures were verified against live Crossref records and the published article body. Records measured light-shift gate fidelities 99.6(1)%, 98.7(2)%, 97.0(3)%, 93.7(3)% for dimensions 2-5, the quadratic error scaling with dimension, and maximal Schmidt-number entanglement certification up to d=5.
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Quantum information carriers, just like most physical systems, naturally occupy high-dimensional Hilbert spaces. Instead of restricting them to a two-level subspace, these high-dimensional (qudit) quantum systems are emerging as a powerful resource for the next generation of quantum processors. Yet harnessing the potential of these systems requires efficient ways of generating the desired interaction between them. Here, we experimentally demonstrate an implementation of a native two-qudit entangling gate up to dimension 5 in a trapped-ion system. This is achieved by generalizing a recently proposed light-shift gate mechanism to generate genuine qudit entanglement in a single application of the gate. The gate seamlessly adapts to the local dimension of the system with a calibration overhead that is independent of the dimension.
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Simulating entangled, many-body quantum systems is notoriously hard, especially in the case of high-dimensional nature of physical underlying objects. In this work, we propose an approach for simulating the Potts model based on the Suzuki-Trotter decomposition that we construct for qudit systems. Specifically, we introduce two qudit-native decomposition schemes: (i) the first utilizes Molmer-Sorensen gate and additional local levels to encode the Potts interactions, while (ii) the second employs an light-shift gate that naturally fits qudit architectures. These decompositions enable a direct and efficient mapping of the Potts model dynamics into hardware-efficient qudit gate sequences for trapped-ion platform. Furthermore, we demonstrate the use of a Suzuki-Trotter approximation with our evolution-into-gates framework, for detecting the dynamical quantum phase transition. Our results establish a pathway toward qudit-based digital quantum simulation of many-body models and provide a new perspective on probing nonanalytic behavior in high-dimensional quantum many-body models.