The use of multilevel information carriers, also known as qudits, is a promising path for exploring scalability of quantum computing devices. Here we present a proof-of-principle realization of a quantum processor register that uses optically addressed $^{171}\mathrm{Yb}^{+}$ ion qudits in a linear trap. The rich level structure of $^{171}\mathrm{Yb}^{+}$ ions allows using the Zeeman sublevels of the quadrupole clock transition at 435.5 nm for efficient and robust qudit encoding. We demonstrate the realization of the universal set of gates consisting of single-qudit rotations and a two-qudit M\o{}lmer-S\o{}rensen operation with a two-ququart system, which is formally equivalent to a universal gate-based four-qubit processor. Our results paves a way toward further studies of more efficient implementations of quantum algorithms with trapped-ion-based processors and, specifically, exploring properties of $^{171}\mathrm{Yb}^{+}$ ion qudits.The use of multilevel information carriers, also known as qudits, is a promising path for exploring scalability of quantum computing devices. Here we present a proof-of-principle realization of a quantum processor register that uses optically addressed $^{171}\mathrm{Yb}^{+}$ ion qudits in a linear trap. The rich level structure of $^{171}\mathrm{Yb}^{+}$ ions allows using the Zeeman sublevels of the quadrupole clock transition at 435.5 nm for efficient and robust qudit encoding. We demonstrate the realization of the universal set of gates consisting of single-qudit rotations and a two-qudit M\o{}lmer-S\o{}rensen operation with a two-ququart system, which is formally equivalent to a universal gate-based four-qubit processor. Our results paves a way toward further studies of more efficient implementations of quantum algorithms with trapped-ion-based processors and, specifically, exploring properties of $^{171}\mathrm{Yb}^{+}$ ion qudits.

arXiv:2210.09121Physical Review AMay 23, 202345 citations

Universal quantum computing with qubits embedded in trapped-ion qudits

Anastasiia S. Nikolaeva, Evgeniy O. Kiktenko, Aleksey K. Fedorov

Recent developments in qudit-based quantum computing, in particular with trapped ions, open interesting possibilities for scaling quantum processors without increasing the number of physical information carriers. Here, we propose a method for compiling quantum circuits in the case, where qubits are embedded into qudits of experimentally relevant dimensionalities, $d=3,...,8$ , for the trapped-ion platform. In particular, we demonstrate how single-qubit, two-qubit, and multiqubit gates can be realized using single-qudit operations and the $\text{M}\o{}\text{lmer-S}\o{}\text{rensen}$ (MS) gate as a basic two-particle operation. We expect that our findings are directly applicable to the current generation of trapped-ion-based qudit processors.Recent developments in qudit-based quantum computing, in particular with trapped ions, open interesting possibilities for scaling quantum processors without increasing the number of physical information carriers. Here, we propose a method for compiling quantum circuits in the case, where qubits are embedded into qudits of experimentally relevant dimensionalities, $d=3,...,8$, for the trapped-ion platform. In particular, we demonstrate how single-qubit, two-qubit, and multiqubit gates can be realized using single-qudit operations and the $\text{M}\o{}\text{lmer-S}\o{}\text{rensen}$ (MS) gate as a basic two-particle operation. We expect that our findings are directly applicable to the current generation of trapped-ion-based qudit processors.

arXiv:2302.02966Physical Review AFeb 21, 202420 citations

The ion trap quantum information processor

Andrew M. Steane

arXiv:quant-ph/9608011Applied Physics BJun 1, 1997322 citations

Two-Qubit Optical Gate in a Mixed-Species Trapped-Ion Quantum Processor

Colin Bruzewicz, Jonathon A. Sedlacek, Jules Stuart +3 more

Bulletin of the American Physical SocietyMay 29, 20180 citations

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

Rowan Brad Quni-Gudzinas

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.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.

Aug 10, 20260 citations

^{171}\mathrm{Yb}^{+}

ion qudits in a linear trap. The rich level structure of

^{171}\mathrm{Yb}^{+}

ions allows using the Zeeman sublevels of the quadrupole clock transition at 435.5 nm for efficient and robust qudit encoding. We demonstrate the realization of the universal set of gates consisting of single-qudit rotations and a two-qudit M\o{}lmer-S\o{}rensen operation with a two-ququart system, which is formally equivalent to a universal gate-based four-qubit processor. Our results paves a way toward further studies of more efficient implementations of quantum algorithms with trapped-ion-based processors and, specifically, exploring properties of

^{171}\mathrm{Yb}^{+}

ion qudits.

d=3,...,8

, for the trapped-ion platform. In particular, we demonstrate how single-qubit, two-qubit, and multiqubit gates can be realized using single-qudit operations and the $\text{M}\o{}\text{lmer-S}\o{}\text{rensen}$ (MS) gate as a basic two-particle operation. We expect that our findings are directly applicable to the current generation of trapped-ion-based qudit processors.