Work

Two-level system loss characterization of NbTi superconducting resonators on Si/SiO2 substrates

Year: 2025

Type: article

Abstract: Superconducting coplanar waveguide (SCPW) resonators, key components for quantum computing and sensing applications, require a high internal quality factor ( Q i ) for effective qubit readout and quantum sensing applications. Minimizing two-level system (TLS) losses, particularly at material interfaces, is critical for gatemon and topological qubits operating at low temperatures and in high magnetic fields. NbTi, a superconducting alloy with a high upper critical field, enables SCPW resonators resilient to such conditions. We fabricated NbTi SCPW resonators on Si/SiO 2 substrates and systematically characterized their TLS-limited quality factors as functions of temperature and microwave photon number. Our results demonstrate that NbTi-based SCPWs on Si/SiO 2 substrates provide a promising platform for developing next-generation quantum circuits. • Successfully fabricated NbTi SCPW resonators on Si/SiO 2 substrates. • Characterized NbTi SCPW across temperature and photon ranges for quantum apps. • Achieved record TLS-limited quality factor Q TLS,0 = 9.21 × 10 4 for SCPW on Si/SiO 2 . • NbTi SCPW on Si/SiO 2 is promising for gatemon and topological qubits.

Source: Current Applied Physics

DOI: 10.1016/j.cap.2025.10.010

Authors: Bongkeon Kim, Yong-Joo Doh

Institution: Gwangju Institute of Science and Technology

Language: English

Topic: Quantum Information and Cryptography

Subfield: Artificial Intelligence

Field: Computer Science

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $2,640

Funders: Gwangju Institute of Science and Technology, National Research Foundation of Korea, Ministry of Science and ICT, South Korea