Graphene Quantum Hall Effect Devices for AC and DC Electrical Metrology

Area of Science:

• Solid State Physics
• Quantum Metrology
• Materials Science

Background:

• Quantum Hall effect (QHE) provides a fundamental resistance standard.
• Existing standards face challenges in alternating current (AC) applications.
• Graphene offers tunable electronic properties for advanced metrology.

Purpose of the Study:

• To evaluate novel graphene-based quantum Hall standards for both direct current (DC) and AC electrical metrology.
• To investigate the AC characteristics, including capacitance and losses, of these new devices.
• To assess the precision of resistance measurements using these standards under both DC and AC conditions.

Main Methods:

• Fabrication of graphene devices functionalized with Cr(CO)3 for charge carrier density control.
• Integration of branched Hall contacts using NbTiN superconducting material.
• Characterization of device capacitances and AC losses.
• Performance evaluation in precision resistance measurements at both DC and AC.

Main Results:

• Demonstration of functional graphene-based quantum Hall standards for both DC and AC.
• Detailed analysis of characteristic capacitances and associated losses in the AC regime.
• Successful precision resistance measurements at both DC and AC, validating device performance.

Conclusions:

• The developed graphene quantum Hall standards are suitable for advanced electrical quantum metrology.
• The functionalization and superconducting contacts enable precise measurements across DC and AC regimes.
• This work advances the development of robust standards for next-generation electrical measurements.