Optical Study of the Stripe-Ordered State

TL;DR

This paper reviews how stripe order influences the optical spectra of La-based cuprates, highlighting a reduction in Josephson plasma frequency and suggesting 2D superconductivity, with implications for understanding stripe effects in various cuprates.

Contribution

It provides a comprehensive review of optical spectral changes due to stripe order in cuprates, emphasizing the impact on Josephson coupling and superconductivity.

Findings

Stripe order reduces Josephson plasma frequency in c-axis spectra.

Stripe effects are observed even without static stripe phases.

In-plane spectra show weak gap features and reduced condensate spectral weight.

Abstract

The effects of the stripe order on the optical spectra of La-based cuprates are reviewed. The main effect on the high Tc superconducting cuprates is to rapidly reduce the Josephson plasma frequency in the c-axis spectrum as a consequence of weakening of the Josephson coupling between CuO2 layers. This points toward a two dimensional (2D) superconductivity in the stripe phase, although it is difficult to realize a 2D superconductivity in real materials. We also discuss the experimental results suggesting the presence of stripe effect in other cuprates even if they do not show the static stripe phase. Compared to the c-axis spectra, the in-plane spectra are not so dramatically affected by the stripe order, showing a weak gap-like feature and reducing the condensate spectral weight.