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arXiv · 2412.08213

Enhancement of superconductivity in electron-hole coexisting Sr$_{1-x}$Eu$_{x}$CuO$_{2+y}$ films

Hang Yan·Ze-Xian Deng·Xue-Qing Yu·Yan-Ling Xiong·Qun Zhu·Ding Zhang·Can-Li Song·Xu-Cun Ma·Qi-Kun Xue
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Abstract

We report transport measurements of infinite-layer cuprate Sr$_{1-x}$Eu$_{x}$CuO$_{2+y}$ films with controlled electron (by trivalent europium) and hole (by interstitial apical oxygen) carriers grown on SrTiO$_3$(001) with molecular beam epitaxy. An unusual enhancement of superconductivity upon moderate electron-hole coexistence in the films is found, which spans over the whole superconducting phase diagram and becomes more prominent in the underdoped regime. The superconductivity exhibits a two-dimensional nature with a thickness of approximately 5.2 nm, irrespective of the varying carriers, confirmed by angle-resolved magnetoresistance measurements and the Berzzinsky-Kosterlitz-Thouless transition. Nevertheless, the electron-hole coexistence enlarges the thermal activation energy of vortex motion that deviates obviously from the usual logarithmic evolution with the magnetic field. Our results offer a promising perspective to understand and enhance the high-temperature superconductivity in cuprates.

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Hang Yan, Ze-Xian Deng, Xue-Qing Yu, Yan-Ling Xiong, Qun Zhu, Ding Zhang, Can-Li Song, Xu-Cun Ma, Qi-Kun Xue. 2024-12-11. Enhancement of superconductivity in electron-hole coexisting Sr$_{1-x}$Eu$_{x}$CuO$_{2+y}$ films. https://arxiv.org/abs/2412.08213

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