Persistence of Entangled States and High Fidelity Quantum Gate Operations in Si/SiGe Spin Qubits at High Temperature

TL;DR

This study demonstrates high-fidelity single- and two-qubit operations in Si/SiGe spin qubits at temperatures up to 750 mK, showing potential for practical quantum computing with integrated cryogenic electronics.

Contribution

It reports the highest operating temperature for Si/SiGe spin qubits with high fidelity, advancing their suitability for scalable quantum processors.

Findings

High-fidelity qubit operations at 750 mK

Successful randomized benchmarking and Bell state tomography at elevated temperatures

Compatibility with integrated cryogenic electronics demonstrated

Abstract

We characterize single- and two-qubit operations in a SiGe quantum dot array, from the perspective of its quantum information processing capabilities. The analysis includes rigorous randomized benchmarking of single- and two-qubit gates, SPAM characterization, and Bell's state tomography, which are all basic functionality required for universal quantum computation. To assess compatibility with integrated cryogenic electronics, we evaluate qubit performance at 350 mK, 500 mK, and 750 mK, with high fidelity single and two qubit operations. The highest temperature, 750 mK, falls within the realistic thermal budget for practical integrated cryogenic electronics and represents the highest operating temperature reported for this qubit platform.