An addressable quantum dot qubit with fault-tolerant control-fidelity.

By Menno Veldhorst, J. C. Hwang, C. Yang, A. Leenstra, B. D. Ronde, Juan Pablo Dehollain, J. Muhonen, Fay Hudson, Kohei M. Itoh, A. Morello and 1 more. Nature Nanotechnology, 2014

885 citations recorded by the source corpus.

Exciting progress towards spin-based quantum computing has recently been made with qubits realized using nitrogen-vacancy centres in diamond and phosphorus atoms in silicon. For example, long coherence times were made possible by the presence of spin-free isotopes of carbon and silicon. However, despite promising single-atom nanotechnologies, there remain substantial challenges in coupling such qubits and addressing them individually. Conversely, lithographically defined quantum dots have an exchange coupling that can be precisely engineered, but strong coupling to noise has severely limited their dephasing times and control fidelities. Here, we combine the best aspects of both spin qubit schemes and demonstrate a gate-addressable quantum dot qubit in isotopically engineered silicon with a control fidelity of 99.6%, obtained via Clifford-based randomized benchmarking and consistent with that required for fault-tolerant quantum computing. This qubit has dephasing time T2* = 120 μs and coherence time T2 = 28 ms, both orders of magnitude larger than in other types of semiconductor qubit. By gate-voltage-tuning the electron g*-factor we can Stark shift the electron spin resonance frequency by more than 3,000 times the 2.4 kHz electron spin resonance linewidth, providing a direct route to large-scale arrays of addressable high-fidelity qubits that are compatible with existing manufacturing technologies.

Subfields: Atomic and Molecular Physics, and Optics, Electrical and Electronic Engineering

View Paper: https://www.semanticscholar.org/paper/bd82ba6c316beb1c87de2f8e501673725c323e69

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In Atomic and Molecular Physics, and Optics

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Citations in the corpus

Cryo-CMOS Circuits and Systems for Quantum Computing Applications (2018, background): “, 4–8-GHz bursts for transmons [13], [14] and >12-GHz bursts for spin qubits [15]–[18].”
Materials challenges and opportunities for quantum computing hardware (2021, background): “Single-electron spin qubits using enriched (28)Si CVD epilayers formed on natural silicon substrates have demonstrated more than an order of magnitude improvement in coherence relative to natural silicon, leading to T2* ~ 120 ms for gate-defined MOS quantum dots (147), T2* ~ 20 ms for gatedefined Si”
Universal Quantum Transducers Based on Surface Acoustic Waves (2015, background): “[41]), it potentially benefits from prolonged dephasing times T⋆2 > 100 μs [81], since nuclear spins are largely absent in isotopically”