Extended Data Fig. 7: STM analysis of LaSiI and nesting vector.
From: Two-dimensional heavy fermions in the van der Waals metal CeSiI
a, STM topographic image of LaSiI, displaying the hexagonal lattice of iodine atoms and surface defects. Scale bar: 8 nm. Conditions: T = 8 K, 100 mV, 50 pA. Inset: Fourier transform of the STM topography, showing the same peak at qAFM ~ 0.28 r.l.u. (dark blue arrow, r.l.u. = reciprocal lattice units) as CeSiI (Fig. 3c), which results from a nesting wavevector. Scale bar: 0.25 r.l.u. b, Line cut of the Fourier transform along kx showing a peak in intensity at qAFM (blue arrows) for LaSiI and CeSiI and in the DFT calculated spectrum of LaSiI. c, Contour plot of the calculated DFT band of LaSiI. The blue arrow indicates the qAFM nesting wavevector between two critical points in the Brillouin zone. d, Simulation of the LaSiI STM Fourier space displaying a peak in intensity at the qAFM nesting wavevector.
