Hybrid rf SQUID qubit based on high kinetic inductance.

Area of Science:

• Quantum Computing
• Superconducting Devices
• Materials Science

Background:

• Superconducting Quantum Interference Devices (SQUIDs) are crucial for quantum computing.
• Developing qubits with desirable properties like small size and high anharmonicity is essential.
• Kinetic inductance in superconducting materials offers a pathway for novel qubit designs.

Purpose of the Study:

• To report the development and microwave characterization of rf SQUID qubits.
• To demonstrate the feasibility of using TiN thin films with high kinetic inductance for qubit fabrication.
• To explore the potential of these hybrid devices for studying dissipation and decoherence mechanisms.

Main Methods:

• Fabrication of rf SQUID qubits using an aluminium-based Josephson junction integrated into a TiN superconducting loop.
• Microwave characterization of the developed qubit systems.
• Utilizing high kinetic inductance properties of the TiN thin film.

Main Results:

• Demonstrated rf SQUID qubits with small physical size.
• Achieved high anharmonicity in the qubit systems.
• Observed small scatter in device parameters, indicating fabrication consistency.
• Successfully realized a non-tunable prototype rf SQUID qubit based on kinetic inductance.

Conclusions:

• The developed rf SQUID qubits represent a promising prototype for quantum computing applications.
• These hybrid devices can serve as valuable tools for investigating fundamental physics of dissipation and decoherence in superconducting nanowires.
• The use of high kinetic inductance TiN films offers a scalable approach for future qubit development.