Operating semiconductor quantum processors with hopping spins

• Published in: Science (American Association for the Advancement of Science) Vol. 385; no. 6707; pp. 447 - 452
• Main Authors: Wang, Chien-An, John, Valentin, Tidjani, Hanifa, Yu, Cécile X, Ivlev, Alexander S, Déprez, Corentin, van Riggelen-Doelman, Floor, Woods, Benjamin D, Hendrickx, Nico W, Lawrie, William I L, Stehouwer, Lucas E A, Oosterhout, Stefan D, Sammak, Amir, Friesen, Mark, Scappucci, Giordano, de Snoo, Sander L, Rimbach-Russ, Maximilian, Borsoi, Francesco, Veldhorst, Menno
• Format: Journal Article
• Language: English
• Published: United States The American Association for the Advancement of Science 26.07.2024
• Subjects: Arrays; Crosstalk; Information processing; Ion traps (instrumentation); Neutral atoms; Quantum computing; Quantum dots; Quantum phenomena; Qubits (quantum computing)
• ISSN: 0036-8075; 1095-9203; 1095-9203
• DOI: 10.1126/science.ado5915

Qubits that can be efficiently controlled are essential for the development of scalable quantum hardware. Although resonant control is used to execute high-fidelity quantum gates, the scalability is challenged by the integration of high-frequency oscillating signals, qubit cross-talk, and heating. Here, we show that by engineering the hopping of spins between quantum dots with a site-dependent spin quantization axis, quantum control can be established with discrete signals. We demonstrate hopping-based quantum logic and obtain single-qubit gate fidelities of 99.97%, coherent shuttling fidelities of 99.992% per hop, and a two-qubit gate fidelity of 99.3%, corresponding to error rates that have been predicted to allow for quantum error correction. We also show that hopping spins constitute a tuning method by statistically mapping the coherence of a 10-quantum dot system. Our results show that dense quantum dot arrays with sparse occupation could be developed for efficient and high-connectivity qubit registers.