Superconductivity and topology of monolayer Fe(Se,Te)
· Invited
Abstract
The origin of enhanced superconductivity over 50 K in the recently discovered FeSe monolayer films grown on SrTiO3 (STO), as compared to 8 K in bulk FeSe, is intensely debated. Many mechanisms, like lattice strain, interfacial coupling, electron doping, have been discussed as possible reasons which can change the superconductivity. Using molecular beam epitaxy (MBE), we are able to manipulate several parameters in monolayer Fe(Se, Te)/STO. In-situ high-resolution angle-resolved photoemission spectroscopy (ARPES) measurement displays how the lattice strain, electron, and chemical doping affect physical properties of monolayer FeSe. We observed enhanced superconductivity accompanying Lifshitz transition in both FeSe and Fe(Se, Te). Moreover, our results provide a clear experimental indication that the Fe(Se, Te) materials are high-temperature topological superconductors in which band topology and superconductivity are integrated intrinsically.
*This work is supported by grants from the Ministry of Science and Technology of China (2015CB921000, 2016YFA0401000, 2015CB921301) and the National Natural Science Foundation of China (11574371, 11274362, 1190020, 11334012, 11274381).
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Presenters
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Yujie Sun
- Institute of Physics, Chinese Academy of Sciences
- Institute of Physics, Chinese Academy of Sciecses