Quasiparticle interference imaging

Quasiparticle interference (QPI) imaging is a technique used in condensed matter physics that allows a scanning tunneling microscope to image the electronic structure of a material and infer information about the momentum space electronic structure from imaging the density of states in real space. In a scanning tunneling microscope, a very sharp metal tip is brought within a few angstrom of a sample.

Source: Wikipedia — Quasiparticle interference imaging (CC BY-SA 4.0)