Towards a quantum resistance standard based on epitaxial graphene

Area of Science:

• Condensed Matter Physics
• Quantum Metrology
• Materials Science

Background:

• The quantum Hall effect is crucial for defining the international resistance standard.
• Current standards rely on silicon and III-V heterostructures, achieving limited precision.
• Graphene's 2D nature makes it a promising candidate for quantum resistance standards.

Purpose of the Study:

• To investigate the potential of monolayer epitaxial graphene for highly accurate quantum resistance metrology.
• To overcome the precision limitations previously observed in graphene-based quantum Hall effect devices.

Main Methods:

• Fabrication of monolayer epitaxial graphene.
• Measurement of Hall resistance quantization at 300 mK under magnetic fields.
• Assessment of graphene's structural integrity, uniformity, mobility, and carrier concentration over large areas.

Main Results:

• Achieved a quantum Hall resistance quantization accuracy of three parts per billion in monolayer epitaxial graphene.
• Demonstrated unprecedented accuracy, four orders of magnitude better than previous graphene results.
• Confirmed structural integrity, uniformity, and reproducible electronic properties across large-scale graphene wafers.

Conclusions:

• Monolayer epitaxial graphene can achieve the high precision required for quantum resistance metrology.
• The demonstrated performance surpasses previous graphene-based efforts and rivals established standards.
• These findings open new avenues for graphene in quantum metrology and other advanced applications.