Extended Data Fig. 6: Comparison between velocity measured from quantum Hall effect, Shubnikov–de Hass oscillations and non-linear transport measurements near charge neutrality.
From: Evidence for Dirac flat band superconductivity enabled by quantum geometry
a dV/dI versus density n and bias current I for device D2 with θ = 1.06º. Peaks due to the Schwinger effect are indicated by the red dashed lines. b Rxx versus n at T = 30, 25, 20, 18, 12, 10, 7, 5 and 2.02 K, respectively (blue to black). Inset: Activation plot of Rxx measured in the quantum Hall νq = 4 valley indicated by the arrow in the main panel taken at B = 4 T. c–d Same as a–b but for device D3. Inset in c: Zoom-in of same data in main panel with background subtracted. Colour scale: black: −1 kΩ; white: 3 kΩ. From blue to black, temperatures in d are T = 10, 6, 4, 2.5, 1.8, 1.2, 0.8, 0.4, 0.1 and 0.03 K. e Plot of vQH versus vNLT for D2 and D3. The dotted line indicates vQH = vNLT.
