Unraveling Enhanced Superconductivity in Single-Layer FeSe through Substrate Surface Terminations.

ABSTRACT: Single-layer FeSe on SrTiO₃(001) substrates shows a superconducting transition temperature much higher than that of bulk FeSe, which has been attributed to factors such as electron doping, interfacial electron-phonon coupling, and electron correlations. To pinpoint the primary driver, we grew single-layer FeSe films on SrTiO₃(001) substrates with coexisting TiO₂ and SrO surface terminations. Scanning tunneling spectroscopy revealed a larger superconducting gap (17.0 meV) on the TiO₂-termination than on the SrO-termination (10.5 meV). Tunneling spectroscopy also showed a larger work function on the SrO surface, resulting in reduced charge transfer to FeSe, as confirmed by angle-resolved photoemission spectroscopy. Scanning transmission electron mi

SUBMITTER: Zou Q 

PROVIDER: S-EPMC12670505 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature