Fig. 5

Anisotropic vortices and vortex lattice transition. a–e Subtracted conductance maps (G_sub) obtained on a 500 Å x 500 Å area with magnetic fields applied parallel to the a-axis, which show elongated vortices on the [100] surface. Red dots indicate the fitted centers of mass of the vortices. Dashed line displays the fit through the centers of mass of the vortices to determine the opening angle β. The color scale corresponds to the normalized subtracted conductance map \(G_{{\mathrm{sub}},{\mathrm{norm}}} = G_{{\mathrm{sub}}}/\) \(\left| {\overline {G_{{\mathrm{sub}}}} } \right|\), where \(\overline {G_{{\mathrm{sub}}}}\) is the mean of the subtracted conductance value over the entire field of view. It ranges from −2 to 2. Scale bar: 100 Å. f Averaged vortex shape obtained by overlaying 90 measured vortices at different fields. \(\phi\) corresponds to the angle with respect to the c-axis. Scale bar: 30 Å; color scale indicates \(G_{{\mathrm{sub}},{\mathrm{norm}}}\) from −1 to 1. g Extracted effective coherence length as a function of angle \(\phi\), with error bars estimated from the uncertainty of the \(G\left( {r,\phi } \right)\sim e^{ - r/\xi \left( \phi \right)}\) fit. h Spatially averaged density of states (see Supplementary Fig. 6 for details) in the vortex core (green), far from the vortex (blue), and their difference (red), which show the existence of the bound states inside the vortex