Surface Josephson plasma waves in a high-temperature superconductor
| Autor: | Adrian Gozar, Ivan Bozovic, Robert Sundling, Xi He, Anthony Bollinger, Qianbo Lu |
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| Rok vydání: | 2020 |
| Předmět: |
Electron density
Photon Materials science Terahertz radiation Physics::Optics FOS: Physical sciences 02 engineering and technology lcsh:Atomic physics. Constitution and properties of matter 01 natural sciences Superconductivity (cond-mat.supr-con) Condensed Matter::Materials Science Condensed Matter - Strongly Correlated Electrons Condensed Matter::Superconductivity Mesoscale and Nanoscale Physics (cond-mat.mes-hall) 0103 physical sciences lcsh:TA401-492 010306 general physics Plasmon Superconductivity Strongly Correlated Electrons (cond-mat.str-el) Condensed Matter - Mesoscale and Nanoscale Physics Condensed matter physics Condensed Matter - Superconductivity Heterojunction Plasma Dissipation 021001 nanoscience & nanotechnology Condensed Matter Physics lcsh:QC170-197 Electronic Optical and Magnetic Materials lcsh:Materials of engineering and construction. Mechanics of materials 0210 nano-technology |
| Zdroj: | npj Quantum Materials, Vol 5, Iss 1, Pp 1-8 (2020) |
| ISSN: | 2397-4648 |
| Popis: | Electron density oscillations with acoustic dispersions and sustained at boundaries between different media provide information about surface and interface properties of hetero-structures. In ultra-thin metallic films these plasmonic excitations are heavily damped. Superconductivity is predicted to reduce dissipation allowing detection of these resonances. Emerging low-loss interface Cooper-pair waves have been studied before, however, the observation of surface-confined Josephson plasmons has remained elusive. Here, we report on generation and coupling to these excitations in an ultrathin single-crystal film of high-temperature superconductor La1.85Sr0.15CuO4. The film becomes brighter than Au below the critical temperature when probed with sub-gap THz photons. We show that the enhanced signal in the superconducting state, which can be visualized with a spatial resolution better than {\lambda}/3,000, originates from near-field coupling of light to surface Josephson plasmons. Our results open a path towards non-invasive investigation of enhanced superconductivity in artificial multilayers, buried interface states in topological hetero-structures, and non-linear phenomena in Josephson devices. Comment: references added; expanded discussion; journal reference |
| Databáze: | OpenAIRE |
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