Scalable, High-Fidelity All-Electronic Control of Trapped-Ion Qubits
C. M. Löschnauer, Jacopo Mosca Toba, A. C. Hughes, Steven A. King, Marius Weber, R. Srinivas, R. Matt, Rustin Nourshargh, D. T. C. Allcock, C. J. Ballance, Clemens Matthiesen, M. Malinowski, T. P. Harty
Abstract
The central challenge of quantum computing is implementing high-fidelity quantum gates at scale. However, many existing approaches to qubit control suffer from a scale-performance trade-off, impeding progress towards the creation of useful devices. Here, we present a vision for an electronically controlled trapped-ion quantum computer that alleviates this bottleneck. Our architecture utilizes shared current-carrying traces and local tuning electrodes in a microfabricated chip to perform quantum gates with low noise and crosstalk regardless of device size. To verify our approach, we experimentally demonstrate low-noise site-selective single- and two-qubit gates in a seven-zone ion trap. We implement electronic single-qubit gates with fidelities <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mo>≥</a:mo><a:mn>99.99912</a:mn><a:mo stretchy="false">(</a:mo><a:mn>8</a:mn><a:mo stretchy="false">)</a:mo><a:mi mathvariant="normal">%</a:mi></a:math> and demonstrate consistent performance with low crosstalk across the device. We also electronically generate two-qubit maximally entangled states with <f:math xmlns:f="http://www.w3.org/1998/Math/MathML" display="inline"><f:mn>99.97</f:mn><f:mo stretchy="false">(</f:mo><f:mn>1</f:mn><f:mo stretchy="false">)</f:mo><f:mi mathvariant="normal">%</f:mi></f:math> fidelity and long-term stable performance over continuous system operation. These state-of-the-art results highlight the potential of our all-electronic approach for coherent control of trapped-ion qubits in large-scale quantum computers.