Conductance Quantum

The conductance of a single perfect quantum channel: 77.48 microsiemens, or its inverse 12.9 kΩ.

Specifications & Metrics

symbol

G0

status

Exact — exact via e and h in the 2019 SI

value

7.748091729 × 10⁻⁵ S

Relative Scale in Constants

Core Principles & Analysis

• A one-atom contact carries current in integer steps of this quantum.
• Observed directly as conductance staircases in gold nanowires at room temperature.
• Exactly e²/h in the 2019 SI, with both defining constants exact.