In-plane anisotropy of the electronic structure for the charge/orbital-ordered state in half-doped manganite with layered structure

TL;DR

This study reveals in-plane anisotropy in the electronic structure of a layered half-doped manganite, showing polarization-dependent charge dynamics linked to charge/orbital ordering and quantum interference effects.

Contribution

It provides the first direct experimental evidence of in-plane electronic anisotropy in a layered manganite, aligning with theoretical predictions.

Findings

Optical conductivity varies with polarization direction.

Smaller energy gap along zigzag ferromagnetic chains.

Charge/orbital ordering influences quantum interference effects.

Abstract

We report on the in-plane anisotropy of the electronic response in the spin/charge/orbital ordered phase of a half-doped layered-structure manganite. The optical conductivity spectra for a single domain of Eu$_{1/2}$% Ca$_{3/2}$MnO$_{4}$ unambiguously show the anisotropic charge dynamics which well corresponds to the theoretical calculation: the optical conductivity with the polarization along the zigzag ferromagnetic chain direction exhibits a smaller gap and a larger intensity at lower energies than that of the perpendicular polarization mostly due to the charge/orbital ordering and the associated quantum interference effect.