Figure 1: Schematic phase diagram of cuprates

Doping dependence of the Mott insulating, superconducting, pseudogap and Fermi liquid phase⁴⁶. A strongly correlated Fermi liquid has a self-energy that scales as Im near the Fermi surface as illustrated schematically in the top-right inset (blue region). Here we show, using angle-resolved photoemission spectroscopy in the doping regime indicated by the vertical line, that the non-Fermi liquid state appears through an angular breakdown of the Fermi liquid as shown schematically in the top-left inset (blue region). This results in arcs of Fermi liquid quasiparticles separated by gapless non-Fermi liquid excitations (red region in the inset) with . These Fermi liquid arcs are different from the Fermi arcs inside the pseudogap phase as there the arcs are separated by (pseudo) gaped excitations. Notice that around 1/8 doping a Fermi liquid re-entrance is realized⁴⁷ (not shown).