A plug-and-play superconducting quantum controller at millikelvin temperatures enables exceeding 99.9% average gate fidelity

TL;DR

This paper introduces a superconducting quantum controller operating at millikelvin temperatures, achieving over 99.9% gate fidelity and addressing control challenges in large-scale superconducting quantum computers.

Contribution

The authors present a novel superconducting quantum controller enabling high-fidelity, all-digital qubit manipulation at millikelvin temperatures with chip-to-chip interconnection.

Findings

Achieved an average Clifford fidelity of 99.9%

Leakage to high energy levels is approximately 10^-4

Estimated gate operation energy is 0.121 fJ

Abstract

The development of large-scale superconducting quantum computing requires efficient in-situ control methods that allow high-fidelity operations at millikelvin temperatures. Superconducting circuits based on Josephson junctions offer a promising solution due to their high speed, low power dissipation, and cryogenic nature. Here, we report a superconducting quantum controller that enables direct chip-to-chip interconnection with qubits at 10 mK and high-fidelity, all-digital manipulation. Randomized benchmarking reveals a uniformly high average Clifford fidelity of 99.9% with leakage to high energy levels on the order of $10^{-4}$, and an estimated average gate operation energy of 0.121 fJ, demonstrating the potential to resolve the control bottleneck in superconducting quantum computing.