Wavelength dependent optical enhancement of superconducting interlayer coupling in La1.885Ba0.115CuO4

TL;DR

This study investigates how different pump wavelengths influence the enhancement of interlayer superconducting coupling in La1.885Ba0.115CuO4, revealing wavelength-dependent effects linked to stripe order melting and superconductivity.

Contribution

It demonstrates wavelength-dependent optical control of superconducting interlayer coupling in a cuprate, highlighting an unconventional competition between stripe order and superconductivity.

Findings

Stronger photo-induced effects at visible wavelengths.

Wavelength tuning enhances interlayer coupling.

Stripe order melting occurs at high energy scales.

Abstract

We analyze the pump wavelength dependence for the photo-induced enhancement of interlayer coupling in La1.885Ba0.115CuO4, which is promoted by optical melting of the stripe order. In the equilibrium superconducting state (T < Tc = 13 K), in which stripes and superconductivity coexist, time-domain THz spectroscopy reveals a photo-induced blue-shift of the Josephson Plasma Resonance after excitation with optical pulses polarized perpendicular to the CuO2 planes. In the striped, non-superconducting state (Tc < T < T_SO = 40 K) a transient plasma resonance similar to that seen below Tc appears from a featureless equilibrium reflectivity. Most strikingly, both these effects become stronger upon tuning of the pump wavelength from the mid-infrared to the visible, underscoring an unconventional competition between stripe order and superconductivity, which occurs on energy scales far above the ordering temperature.