Restoring Interlayer Josephson Coupling in La_{1.885}Ba_{0.115}CuO_4 by Charge Transfer Melting of Stripe Order

TL;DR

This study demonstrates that photoinduced charge transfer can rapidly melt stripe order in La_{1.885}Ba_{0.115}CuO_4, leading to enhanced interlayer superconducting coupling without structural damage, revealing a pathway to control high-temperature superconductivity.

Contribution

It shows that charge transfer excitation can promptly melt stripe order and enhance superconductivity in LBCO, providing new insights into controlling high-temperature superconductivity.

Findings

Charge order melting occurs within 2 ps after photoexcitation.

Enhanced superconducting interlayer coupling is observed following charge order melting.

The process saturates at a fluence of about 0.5 mJ/cm2.

Abstract

We show that disruption of charge-density-wave (stripe) order by charge transfer excitation, enhances the superconducting phase rigidity in La_{1.885}Ba_{0.115}CuO_4 (LBCO). Time-Resolved Resonant Soft X-Ray Diffraction demonstrates that charge order melting is prompt following near-infrared photoexcitation whereas the crystal structure remains intact for moderate fluences. THz time-domain spectroscopy reveals that, for the first 2 ps following photoexcitation, a new Josephson Plasma Resonance edge, at higher frequency with respect to the equilibrium edge, is induced indicating enhanced superconducting interlayer coupling. The fluence dependence of the charge-order melting and the enhanced superconducting interlayer coupling are correlated with a saturation limit of about 0.5 mJ/cm2. Using a combination of x-ray and optical spectroscopies we establish a hierarchy of timescales between enhanced superconductivity, melting of charge order and rearrangement of the crystal structure.