Metallic stripes and the universality of the anomalous half-breathing phonon in high-Tc cuprates

TL;DR

This paper proposes that the anomalous high-frequency phonon behavior in cuprate superconductors is due to enhanced electronic polarizability from metallic stripes, challenging previous interpretations and predicting specific temperature and momentum dependencies.

Contribution

It introduces a new explanation for phonon anomalies based on stripe-induced polarizability, contrasting with the transverse stripe fluctuation model.

Findings

Anomalies occur at momenta parallel to stripes.

Doping dependence explained by stripe model.

Temperature affects phonon line-width and anomaly spread.

Abstract

We demonstrate that the strong anomalies in the high frequency LO-phonon spectrum in cuprate superconductors can in principle be explained by the enhanced electronic polarizability associated with the self-organized one dimensionality of metallic stripes. Contrary to the current interpretation in terms of transversal stripe fluctuations, the anomaly should occur at momenta parallel to the stripes. The doping dependence of the anomaly is naturally explained, and we predict that the phonon line-width and the spread of the anomaly in the transverse momentum decrease with increasing temperature while high resolution measurements should reveal a characteristic substructure to the anomaly.