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Superconductivity in an Orbital-Reoriented SnAs Square Lattice: A Case Study of Li0.6Sn2As2 and NaSnAs |
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| Authors: | Junjie Wang Prof?Dr Tianping Ying Dr Jun Deng Dr Cuiying Pei Dr Tongxu Yu Dr Xu Chen Yimin Wan Mingzhang Yang Dr Weiyi Dai Dr Dongliang Yang Prof?Dr Yanchun Li Prof?Dr Shiyan Li Prof?Dr Soshi Iimura Prof?Dr Shixuan Du Prof?Dr Hideo Hosono Prof?Dr Yanpeng Qi Prof?Dr Jian-gang Guo |
| Institution: | 1. Institute of Physics and University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100190 China
These authors contributed equally to this work.;2. Institute of Physics and University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100190 China;3. School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210 China ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, Shanghai, 201210 China Shanghai Key Laboratory of High-resolution Electron Microscopy, ShanghaiTech University, Shanghai, 201210 China These authors contributed equally to this work.;4. Gusu Laboratory of Materials, Jiangsu, 215123 China Suzhou Laboratory, Jiangsu, 215123 China;5. State Key Laboratory of Surface Physics, Department of Physics, Fudan University, Shanghai, 200438 China;6. Beijing Synchrotron Radiation Facility and Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049 China;7. National Institute for Materials Science (NIMS), Tsukuba, Ibaraki, 305-0047 Japan;8. Institute of Physics and University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100190 China Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808 China;9. School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210 China |
| Abstract: | Searching for functional square lattices in layered superconductor systems offers an explicit clue to modify the electron behavior and find exotic properties. The trigonal SnAs3 structural units in SnAs-based systems are relatively conformable to distortion, which provides the possibility to achieve structurally topological transformation and higher superconducting transition temperatures. In the present work, the functional As square lattice was realized and activated in Li0.6Sn2As2 and NaSnAs through a topotactic structural transformation of trigonal SnAs3 to square SnAs4 under pressure, resulting in a record-high Tc among all synthesized SnAs-based compounds. Meanwhile, the conductive channel transfers from the out-of-plane pz orbital to the in-plane px+py orbitals, facilitating electron hopping within the square 2D lattice and boosting the superconductivity. The reorientation of p-orbital following a directed local structure transformation provides an effective strategy to modify layered superconducting systems. |
| Keywords: | Charge Redistribution High Pressure Orbital Reorientation SnAs Square Lattice Superconductivity |