Fig. 2: Electronic phases of NaYbSe2 under pressure.
The upper figure illustrates the predicted phases: the charge-transfer or band insulator, the Kondo semimetal (Kondo), the heavy-fermion metal (HF), and the superconductivity (SC). The pressures denote a rough boundary of these phases from experiment19. a–c The DFT+DMFT spectral functions at 10 K for 60, 75, and 100 GPa, respectively. d–f The corresponding density of states on two inequivalent Yb ions, showing the development of a sharp quasiparticle peak of Yb1-4f electrons. The inset in d is an enlarged plot over a smaller energy window to show the pseudogap structure near the Fermi energy at 60 GPa. The inset in e plots the full width at half maximum (FWHM) of the Yb1 quasiparticle peak as a function of pressure, where the solid line is a linear extrapolation giving a transition at about 73 GPa.
