A critical reexamination of the non-reciprocal x-ray gyrotropy in V$_2$O$_3$

TL;DR

This paper critically reexamines claims of non-reciprocal x-ray gyrotropy in V$_2$O$_3$, questioning previous experimental evidence and emphasizing the need for more controlled tests to confirm such effects in this key correlated material.

Contribution

It provides a critical review of experimental evidence for non-reciprocal x-ray gyrotropy in V$_2$O$_3$ and suggests further experiments to clarify its existence.

Findings

Highlights paradoxical consequences of claimed non-reciprocal effects

Notes absence of expected linear dichroism in data

Recommends more controlled experiments for confirmation

Abstract

We critically review the experimental determination of the nonreciprocal x-ray gyrotropy in the monoclinic antiferromagnetic insulating phase of V$_2$O$_3$ highlighting some of its paradoxical consequences. We also note the apparent absence of a normal (non magnetic) linear dichroism in the data and speculate on the possible reasons for it. Given the importance of the implications of a non reciprocal effect for the physics of V$_2$O$_3$, one of the paradigmatic strongly correlated system, we point up the need for at least repeating the experiment under better controlled conditions and suggest possible tests for establishing unambiguously its existence.