Low-energy V t2g orbital excitations in NdVO3

TL;DR

This study investigates the low-energy orbital excitations in NdVO3 using resonant inelastic x-ray scattering, revealing a temperature-dependent collective excitation linked to the bi-orbiton phenomenon.

Contribution

It identifies a low-energy collective orbital excitation in NdVO3 that cannot be explained by crystal-field models, highlighting the role of bi-orbitons.

Findings

Observation of a ~0.4 eV feature attributed to V t2g excitations.

The feature's intensity peaks in the orbitally-ordered phase.

The excitation is suppressed at low temperatures.

Abstract

The electronic structure of NdVO3, YVO3 has been investigated as a function of sample temperature using resonant inelastic soft x-ray scattering at the V L3-edge. Most of the observed spectral features are in good agreement with an atomic crystal-field multiplet model. However, a low energy feature is observed at ~0.4 eV that cannot be explained by crystal-field arguments. The resonant behaviour of this feature establishes it as due to excitations of the V t2g states. Moreover, this feature exhibits a strong sample temperature dependence, reaching maximum intensity in the orbitally-ordered phase of NdVO3, before becoming suppressed at low temperatures. This behaviour indicates that the origin of this feature is a collective orbital excitation, i.e. the bi-orbiton.