Optical Excitation of Josephson Plasma Solitons in a Cuprate Superconductor


Optical Excitation of Josephson Plasma Solitons in a Cuprate Superconductor

Dienst, A.; Casandruc, E.; Zhang, L.; Eckstein, M.; Fausti, D.; Hoffmann, M.; Khanna, V.; Dean, N.; Gensch, M.; Winnerl, S.; Seidel, W.; Pyon, S.; Takayama, T.; Takagi, H.; Cavalleri, A.

Josephson Plasma Waves are linear electromagnetic modes that propagate along the planes of cuprate superconductors, sustained by oscillatory tunnelling supercurrents. These waves exhibit a plasmonic resonance in the GHz , to THz frequency range, depending on the interlayer coupling strength. For strong electromagnetic fields, the supercurrents approach their critical value and the electrodynamics become highly nonlinear , . Josephson Plasma Solitons (JPS) are breather excitations , that emerge in this regime, bound vortex/antivortex pairs that self-localize , , and propagate without dispersion. We experimentally excite such solitons using intense narrowband radiation from an infrared Free Electron Laser, tuned to the 2-THz Josephson Plasma Resonance of La1.84Sr0.16CuO4. The JPS is revealed by the appearance of long-lived transparency window in the spectral region immediately below the plasma resonance, which is opaque to small-amplitude waves. This reshaping of the optical properties originates from Fano-type coupling between probe waves and the JPS. Optical control of solitonic excitations in superconductors opens up possibilities in THz opto-plasmonics or in the manipulation of high-Tc superconductivity.

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Permalink: https://www.hzdr.de/publications/Publ-17836
Publ.-Id: 17836