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.
@article{arxiv.1505.02167,
title = {Wavelength dependent optical enhancement of superconducting interlayer coupling in La1.885Ba0.115CuO4},
author = {E. Casandruc and D. Nicoletti and S. Rajasekaran and Y. Laplace and V. Khanna and G. D. Gu and J. P. Hill and A. Cavalleri},
journal= {arXiv preprint arXiv:1505.02167},
year = {2015}
}