Resonant inelastic x-ray scattering study of hole-doped manganites La1-xSrxMnO3 (x=0.2 and 0.4)

TL;DR

This study uses resonant inelastic x-ray scattering to investigate electronic excitations in hole-doped manganites La1-xSrxMnO3, revealing doping effects, persistence of the Mott gap, and anisotropic low-energy excitations linked to orbital characteristics.

Contribution

First observation of doping effects on electronic excitations in strongly correlated manganites using RIXS, highlighting changes in the Mott gap and anisotropic spectral features.

Findings

Doping introduces spectral weight below the Mott gap.

The Mott gap persists despite doping.

Low-energy excitations are anisotropic and temperature-dependent.

Abstract

Electronic excitations near the Fermi energy in the hole doped manganese oxides (La1-xSrxMnO3, x=0.2 and 0.4) have been elucidated by using the resonant inelastic x-ray scattering (RIXS) method. A doping effect in the strongly correlated electron systems has been observed for the first time. The scattering spectra show that a salient peak appears in low energies indicating the persistence of the Mott gap. At the same time, the energy gap is partly filled by doping holes and the energy of the spectral weight shifts toward lower energies. The excitation spectra show little change in the momentum space as is in undoped LaMnO3, but the scattering intensities in the low energy excitations of x=0.2 are anisotropic as well as temperature dependent, which indicates a reminiscence of the orbital nature.