Possible zero sound in layered perovskites with ferromagnetic $s$-$d$ exchange interaction

TL;DR

This paper investigates the conditions under which zero sound can be observed in layered perovskites with ferromagnetic $s$-$d$ exchange interactions, highlighting the importance of antiferromagnetic sign of the interaction for zero sound propagation.

Contribution

It provides a theoretical analysis of zero sound in layered perovskites, predicting its observability depending on the sign of the $s$-$d$ exchange interaction and specific material properties.

Findings

Zero sound propagates only with antiferromagnetic $s$-$d$ interaction.

Zero sound appears as a thermally activated dissipation mode in certain materials.

Materials with 4$s$ and 3$d$ levels near the $p$-level of chalcogenide are promising for observing zero sound.

Abstract

We analyze the conditions for observation of zero sound in layered perovskites with transition metal ion on chalcogenide oxidizer. We conclude that propagation of zero sound is possible only for anti-ferromagnetic sign of the $s$-$d$ interaction. If the $s$-$d$ exchange integral $J_{sd}$ has antiferromagnetic sign, as it is perhaps in the case for layered cuprates, zero sound is a thermally activated dissipation mode,which generates only "hot spots" in the Angle Resolved Photoemission Spectroscopy (ARPES) data along the Fermi contour. We predict that zero sound will be observable for transition metal perovskites with 4$s$ and 3$d$ levels close to the $p$-level of the chalcogenide. The simultaneous lack of superconductivity, the appearance of hot spots in ARPES data, and the proximity of the three named levels, represents the significant hint for the choice of material to be investigated.