Operation of a high-frequency, phase-slip qubit.

Area of Science:

• Quantum Computing
• Superconducting Circuits
• Materials Science

Background:

• Aluminum-based Josephson junctions are standard for superconducting qubit control.
• Constriction-based junctions offer alternative nonlinearity for protected qubits and high-temperature operation.
• Incorporating larger energy gap superconductors into qubits has been difficult due to parameter control and low lifetimes.

Purpose of the Study:

• To demonstrate titanium nitride (TiN) as a controllable and promising qubit platform.
• To explore the use of TiN junctions for quantum phase slip-based superconducting qubits.
• To investigate the performance of TiN-based qubits at higher temperatures and with longer lifetimes.

Main Methods:

• Fabrication of superconducting qubits using TiN constriction-based Josephson junctions.
• Operation of the qubit at zero flux, with frequency determined by qubit inductance (~17 GHz).
• Performing qubit readout, coherent control, and lifetime measurements.

Main Results:

• Demonstrated TiN junctions as a controllable qubit platform.
• Achieved qubit lifetimes exceeding 60 microseconds.
• Successfully operated the qubit at temperatures above 300 mK.

Conclusions:

• TiN-based Josephson junctions are a viable tool for superconducting quantum information processing.
• TiN junctions open new possibilities for designing novel superconducting qubits.
• This work facilitates advancements in high-temperature and high-frequency superconducting quantum technologies.