Fluxonium qubits for ultra-high-fidelity and scalable quantum processors

Monday, May 17, 2021 2:30 pm - 2:30 pm EDT (GMT -04:00)

IQC Colloquium - Chunqing Deng, Quantum Scientist and Head of the Experimental Group Alibaba Quantum Laboratory

The success of superconducting quantum computing (SQC) has so far been largely built upon the transmon qubit. Finding an alternative qubit that drastically outperforms transmon represents one of the most fundamental and exciting frontiers of SQC. The fluxonium qubit stands out as a promising candidate, due to its long coherence times and large anharmonicity. Furthermore, fluxonium can be directly integrated into the existing circuit-QED schemes for scaling. For these reasons, fluxonium is our qubit platform of choice at Alibaba Quantum Laboratory.

In this talk, I will present our design and experiments of a 2D fluxonium circuit, which exhibits high coherence, high tunability and strong coupling. With T1 and T2 > 100 us at around the sweet spot, we achieve a dielectric loss tangent as low as 0.7e-6, approaching the state of the art. Using a high-bandwidth flux bias, we demonstrate robust qubit reset and readout, together with fast one- and two-qubit gates. In particular, we realized an iSWAP two-qubit gate, achieving 0.995 fidelity. Our work paves the path toward a fluxonium-based, ultra-high-fidelity multi-qubit processor.

Bio: Chunqing Deng is a Quantum Scientist at Alibaba Quantum Lab (AQL). He received his BSc from Peking University in 2008 and his PhD from University of Waterloo in 2015. After that, he joined D-Wave Systems Inc. and became a lead scientist there. At D-Wave Systems, Chunqing worked on improving the coherence of superconducting qubits and developing novel qubit-qubit interactions for future-generation adiabatic quantum processors. He is currently leading the experimental quantum computing effort at Alibaba to build a quantum computer for real-world problems.

Join Zoom Meeting

Meeting ID: 946 2186 4170
Passcode: hJtSUd3

Add event to calendar

Apple   Google   Office 365   Outlook   Outlook.com   Yahoo