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arXiv · 1606.09358

Universal Substrate Effect on the Superconductivity of FeSe Monolayer Films

Slavko Rebec·Tao Jia·Chaofan Zhang·Makoto Hashimoto·Donghui Lu·Robert Moore·Zhixun Shen
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Abstract

To elucidate the mechanisms behind the enhanced $T_c$ in monolayer (1ML) FeSe on SrTiO$_3$ (STO), we grew highly strained 1ML FeSe on the rectangular (100) face of rutile TiO$_2$, and observed the coexistence of replica bands and superconductivity with a $T_c$ of 63 K. From the similar $T_c$ between this system and 1ML FeSe on STO (001), we conclude that strain and dielectric constant are likely unimportant to the enhanced $T_c$ in these systems. A systematic comparison of 1ML FeSe on TiO$_2$ with other systems in the FeSe family shows that while charge transfer alone can enhance $T_c$, it is only with the addition of interfacial electron-phonon coupling that $T_c$ can be increased to the level seen in 1ML FeSe on STO.

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Slavko Rebec, Tao Jia, Chaofan Zhang, Makoto Hashimoto, Donghui Lu, Robert Moore, Zhixun Shen. 2016-06-30. Universal Substrate Effect on the Superconductivity of FeSe Monolayer Films. https://doi.org/10.1103/physrevlett.118.067002

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