Jahn-Teller versus quantum effects in the spin-orbital material LuVO3

TL;DR

This study combines neutron and x-ray scattering to determine that Jahn-Teller distortions, rather than quantum orbital effects, dominate the spin-orbital ground state and excitations in LuVO3, clarifying a long-standing debate.

Contribution

It provides definitive experimental evidence favoring Jahn-Teller distortions over quantum orbital effects in LuVO3 using polarized neutron scattering and detailed magnetic excitation analysis.

Findings

Jahn-Teller distortions are the primary driver of the orbital physics in LuVO3.

Quantum effects in orbitals are not the dominant mechanism in this material.

Magnetic excitation data supports classical orbital behavior over quantum models.

Abstract

We report on combined neutron and resonant x-ray scattering results, identifying the nature of the spin-orbital ground state and magnetic excitations in LuVO3 as driven by the orbital parameter. In particular, we distinguish between models based on orbital Peierls dimerization, taken as a signature of quantum effects in orbitals, and Jahn-Teller distortions, in favor of the latter. In order to solve this long-standing puzzle, polarized neutron beams were employed as a prerequisite in order to solve details of the magnetic structure, which allowed quantitative intensity-analysis of extended magnetic excitation data sets. The results of this detailed study enabled us to draw definite conclusions about classical vs quantum behavior of orbitals in this system and to discard the previous claims about quantum effects dominating the orbital physics of LuVO3 and similar systems.