Sánchez-Barriga, J.; Ovsyannikov, R.; Fink, J.: Strong Spin Dependence of Correlation Effects in Ni Due to Stoner Excitations. Physical Review Letters 121 (2018), p. 267201/1-6
10.1103/PhysRevLett.121.267201
Open Accesn Version
Abstract:
Using high-resolution angle-resolved photoemission, we observe a strong spin-dependent renormalization and lifetime broadening of the quasiparticle excitations in the electronic band structure of Ni(111) in an energy window of ∼0.3 eV below the Fermi level. We derive a quantitative result for the spin-dependent lifetime broadening by comparing the scattering rates of majority and minority d states, and further show that spin-dependent electron correlations are instead negligible for sp states. From our analysis we experimentally determine the effective on-site Coulomb interaction U caused by Stoner-like interband transitions between majority and minority d states. The present results demonstrate the remarkable impact of spin-dependent electron correlation effects originating from single-particle excitations in a prototypical 3d transition metal, paving the way for further refinement of current many-body theoretical approaches.