Details

Autor(en) / Beteiligte

• Peng, R.
• Xu, H. C.
• Tan, S. Y.
• Cao, H. Y.
• Xia, M.
• Shen, X. P.
• Huang, Z. C.
• Wen, C.H.P.
• Song, Q.
• Zhang, T.
• Xie, B. P.
• Gong, X. G.
• Feng, D. L.

Titel

Tuning the band structure and superconductivity in single-layer FeSe by interface engineering

Ist Teil von

• Nature communications, 2014-09, Vol.5 (1), p.5044-5044, Article 5044

Ort / Verlag

London: Nature Publishing Group UK

Erscheinungsjahr

2014

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The interface between transition metal compounds provides a rich playground for emergent phenomena. Recently, significantly enhanced superconductivity has been reported for single-layer FeSe on Nb-doped SrTiO 3 substrate. Yet it remains mysterious how the interface affects the superconductivity. Here we use in situ angle-resolved photoemission spectroscopy to investigate various FeSe-based heterostructures grown by molecular beam epitaxy, and uncover that electronic correlations and superconducting gap-closing temperature ( T g ) are tuned by interfacial effects. T g up to 75 K is observed in extremely tensile-strained single-layer FeSe on Nb-doped BaTiO 3 , which sets a record high pairing temperature for both Fe-based superconductor and monolayer-thick films, providing a promising prospect on realizing more cost-effective superconducting device. Moreover, our results exclude the direct correlation between superconductivity and tensile strain or the energy of an interfacial phonon mode, and highlight the critical and non-trivial role of FeSe/oxide interface on the high T g , which provides new clues for understanding its origin. Individual layers of FeSe grown on SrTiO3 superconduct at far higher temperatures than in bulk, but the effect of the film-substrate interface is poorly understood. Peng et al . find that modifying this interface has a significant non-trivial effect on the superconducting characteristics of FeSe films.