T. Machida, Y. Kohsaka, K. Matsuoka, K. Iwaya, T. Hanaguri & T. Tamegai
Abstract
(a,b) Differential conductance maps at energy E=+10 meV in magnetic fields B=0 and 11 T, respectively. White arrows in a denote the Cu–O bonding directions. Vortices and their internal structures (vortex checkerboard) are clearly imaged in b. (c,d) Differential conductance maps at E=−10 meV taken in B=0 and 11 T. Scale bars, 50 Å (a–d), and the colour scales are in nano siemens (nS). The tunnelling conductance at each location was obtained by numerical differentiation of the current–voltage characteristics and by post-smoothing with the energy window of ±2 meV. (e) Comparison between tunnelling spectra taken at B=0 T (open symbols) and 11 T (solid symbols). Red and blue data depict the spectra spatially averaged over the regions near vortices and far from vortices, respectively. (f) Schematic illustration of the excitation gap in momentum-space showing the dichotomy between the d-wave superconductivity near the node (light blue area) and the antinodal states governed by the pseudogap (yellow area). These two regimes are separated by the line connecting (π/a0, 0) and (0, π/a0), where a0 denotes Cu–O–Cu distance.
Abstract URL: http://www.nature.com/ncomms/2016/160527/ncomms11747/full/ncomms11747.html