The electronic structure of La$_{1-x}$Sr$_{x}$MnO$_{3}$ thin films and its $T_c$ dependence as studied by angle-resolved photoemission

TL;DR

This study uses angle-resolved photoemission spectroscopy to explore how the electronic structure of La$_{1-x}$Sr$_{x}$MnO$_{3}$ thin films correlates with their transition temperature, revealing non-rigid band shifts related to kinetic energy optimization.

Contribution

It provides new insights into the electronic structure changes associated with $T_c$ variations, challenging the rigid band shift model in manganite thin films.

Findings

Spectral weight at a specific ${f k}$-point correlates with $T_c$.

The ${f k}$-point with the sharpest Fermi level step is consistent across samples.

Electronic structure changes are not described by simple rigid band shifts.

Abstract

We present angle-resolved photoemission spectroscopy results for thin films of the three-dimensional manganese perovskite La$_{1-x}$Sr$_{x}$MnO$_{3}$. We show that the transition temperature ($T_c$) from the paramagnetic insulating to ferromagnetic metallic state is closely related to details of the electronic structure, particularly to the spectral weight at the ${\bf k}$-point, where the sharpest step at the Fermi level was observed. We found that this ${\bf k}$-point is the same for all the samples, despite their different $T_c$. The change of $T_c$ is discussed in terms of kinetic energy optimization. Our ARPES results suggest that the change of the electronic structure for the samples having different transition temperatures is different from the rigid band shift.