Strategies for Superconducting Transmon Qubits with Millisecond T$$_1$$ Relaxation Time

Conference · Wed Apr 09 00:00:00 EDT 2025 · No journal information

DOI:https://doi.org/10.2172/2553020· OSTI ID:2553020

Bal, Mustafa ^[1]; Murthy, Akshay ^[1]; Crisa, Francesco ^[1]; Garattoni, Sabrina ^[1]; Zhu, Shaojiang ^[1]; Bafia, Daniel ^[1]; Panthee, Jasmine ^[1]; Sung, Zuhawn ^[1]; Lee, Jae Yel ^[1]; Van Zanten, David ^[2]; Nekrashevich, Ivan ^[1]; Lunin, Andrei ^[1]; Romanenko, Alexander ^[1]; Grassellino, Anna ^[1]

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1. Unlisted
2. Unlisted"

Significant strides have been made in extending qubit lifetimes by mitigating lossy materials at various surfaces and interfaces of superconducting transmon qubits. We have recently demonstrated a five-fold improvement of T$$_1$$ energy relaxation time by encapsulating the Nb surface to prevent native oxide formation. To further extend qubit coherence to millisecond timescales and beyond, we are actively exploring novel strategies. Such strategies include substrate preparation, alternative materials as low loss platforms, novel non-oxide forming low loss capping layers, optimized qubit designs & qubit packaging, and optimized Josephson junction materials, processing, and design. Qubit relaxation time T$$_1$$ measurements will be reported with best T$$_1$$’s in excess of a millisecond. This material is based upon work supported by the U.S. Department of Energy, Office of Science, National Quantum Information Science Research Centers, Superconducting Quantum Materials and Systems Center (SQMS) under contract number DE-AC02-07CH11359.

• Research Organization: Unlisted; Unlisted"
• Sponsoring Organization: US Department of Energy
• DOE Contract Number: 89243024CSC000002
• OSTI ID: 2553020
• Report Number(s): FERMILAB-SLIDES-25-0051-SQMS; oai:inspirehep.net:2909836
• Resource Type: Conference presentation
• Conference Information: Journal Name: No journal information
• Country of Publication: United States
• Language: English

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