Hamiltonian phase error in resonantly driven CNOT gate above the fault-tolerant threshold
Journal
npj Quantum Information
Journal Volume
10
Journal Issue
1
Start Page
8
ISSN
2056-6387
Date Issued
2024-01-11
Author(s)
Yi-Hsien Wu
Leon C. Camenzind
Akito Noiri
Kenta Takeda
Takashi Nakajima
Takashi Kobayashi
Chien-Yuan Chang
Amir Sammak
Giordano Scappucci
Seigo Tarucha
Abstract
Because of their long coherence time and compatibility with industrial foundry processes, electron spin qubits are a promising platform for scalable quantum processors. A full-fledged quantum computer will need quantum error correction, which requires high-fidelity quantum gates. Analyzing and mitigating gate errors are useful to improve gate fidelity. Here, we demonstrate a simple yet reliable calibration procedure for a high-fidelity controlled-rotation gate in an exchange-always-on Silicon quantum processor, allowing operation above the fault-tolerance threshold of quantum error correction. We find that the fidelity of our uncalibrated controlled-rotation gate is limited by coherent errors in the form of controlled phases and present a method to measure and correct these phase errors. We then verify the improvement in our gate fidelities by randomized benchmark and gate-set tomography protocols. Finally, we use our phase correction protocol to implement a virtual, high-fidelity, controlled-phase gate.
Publisher
Springer Science and Business Media LLC
Type
journal article