4.2 K sensitivity-tunable radio frequency reflectometry of a physically defined p-channel silicon quantum dot

Area of Science:

• Quantum Computing
• Solid-State Physics
• Nanotechnology

Background:

• Quantum dots are essential for quantum computing.
• Accurate measurement of quantum dots is crucial for device development.
• Radio frequency reflectometry offers a potential method for quantum dot characterization.

Purpose of the Study:

• To demonstrate the measurement of p-channel silicon-on-insulator quantum dots.
• To optimize radio frequency reflectometry for quantum dot characterization at liquid helium temperatures.
• To investigate the impact of gate design on reflectometry efficiency.

Main Methods:

• Utilized a radio frequency (rf) reflectometry circuit with two tunable GaAs varactors.
• Performed measurements on p-channel silicon-on-insulator quantum dots at liquid helium temperatures (4.2 K).
• Analyzed Coulomb diamond observations and discussed rf leakage from top gates in MOS nanostructures.

Main Results:

• Successfully observed Coulomb diamonds at 4.2 K under optimal matching and high signal-to-noise conditions.
• Demonstrated the effectiveness of the rf reflectometry setup for characterizing quantum dots.
• Identified rf leakage from large top gates as a factor affecting reflectometry efficiency.

Conclusions:

• The developed rf reflectometry technique enables sensitive and fast readout of quantum dots.
• This method is suitable for multi-gate architectures and multi-qubit platforms.
• The findings contribute to advancing the development of scalable quantum computing hardware.