Gatemon qubit revisited for improved reliability and stability

Systematic study of gatemon frequency stability, hysteresis, dephasing, and shunt-capacitor design.

Key Results

Reliable qubit-frequency placement with 1 MHz precision across a range of several gigahertz.
Grounded shunt-capacitor gatemons were more stable than floating-capacitor designs.
Stability and dephasing remained strongly frequency- and device-design-dependent.