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Optically induced superconductivity in stripedLa2−xBaxCuO4by polarization-selective excitation in the near infrared

Authors :
G. D. Gu
Andrea Cavalleri
C. R. Hunt
Yannis Laplace
Stefan Kaiser
Daniele Nicoletti
John Hill
S. S. Dhesi
Eliza Casandruc
Vikaran Khanna
Source :
Physical Review B. 90
Publication Year :
2014
Publisher :
American Physical Society (APS), 2014.

Abstract

We show that superconducting interlayer coupling, which coexists with and is depressed by stripe order in La1.885Ba0.115CuO4, can be enhanced by excitation with near-infrared laser pulses. For temperatures lower than Tc = 13 K, we observe a blue-shift of the equilibrium Josephson plasma resonance, detected by terahertz-frequency reflectivity measurements. Key to this measurement is the ability to probe the optical properties at frequencies as low as 150 GHz, detecting the weak interlayer coupling strengths. For T > Tc a similar plasma resonance, absent at equilibrium, is induced up to the spin-ordering temperature TSO = 40 K. These effects are reminiscent but qualitatively different from the light-induced superconductivity observed by resonant phonon excitation in La1.675Eu0.2Sr0.125CuO6.5. Importantly, enhancement of the below-Tc interlayer coupling and its appearance above Tc are preferentially achieved when the near-infrared pump light is polarized perpendicular to the superconducting planes, likely due to more effective melting of stripe order and the less effective excitation of quasiparticles from the Cooper pair condensate when compared to in-plane excitation.

Details

ISSN :
1550235X and 10980121
Volume :
90
Database :
OpenAIRE
Journal :
Physical Review B
Accession number :
edsair.doi...........2cee54ddb3fe703201a2f64a5917e4a1
Full Text :
https://doi.org/10.1103/physrevb.90.100503