Figure 23.

Summary of the precision measurements of (a) ${\rho }_{xx}$ and (b) the QAHE over the previous few years. Applied currents vary, and the following MTI measurements are represented: 2018 NIST/Stanford (purple),⁴²⁴ PTB/UW (black),⁴²² 2022 NIST/Stanford (red and blue),⁴²⁷ and 2022 NMIJ and partners (olive).⁴²³ The light green region in panel (b) marks the boundary for data points going beneath one part in 10⁷. All error bars represent $k=1$ type A and B combined uncertainties. Adapted with permission under Creative Commons Attribution 4.0 International license from ref 427. Copyright 2022 American Physical Society.