Systematic Development of the Spectral Function in the 3d1 Mott-Hubbard System Ca1−xSrxVO3

Abstract

We present an experimental manifestation of how the single-particle density of states around the Fermi level $\left(E_F\right)$ changes near a Mott transition. In a metallic perovskite-type ${3d}^1$ Mott-Hubbard system ${\mathrm{Ca}}_{1-x}{\mathrm{Sr}}_x{\mathrm{VO}}_3$, as one decreases $x$ the spectral weight of the coherent band near $E_F$ is gradually transferred to that of the precursor of the lower Hubbard band $\sim$2 eV below $E_F$. The momentum dependence of the quasiparticle self-energy and hence the long-range exchange or correlation is shown to become progressively important as one approaches the Mott transition from the metallic side.