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arXiv · 2301.03240

Superconductivity in an Orbital-reoriented SnAs Square Lattice: a Case Study of Li0.6Sn2As2 and NaSnAs

Junjie Wang·Tianping Ying·Jun Deng·Cuiying Pei·Tongxu Yu·Xu Chen·Yimin Wan·Mingzhang Yang·Weiyi Dai·Dongliang Yang·Yanchun Li·Shiyan Li·Soshi Iimura·Shixuan Du·Hideo Hosono·Yanpeng Qi·Jian-gang Guo
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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 superconductors.

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Junjie Wang, Tianping Ying, Jun Deng, Cuiying Pei, Tongxu Yu, Xu Chen, Yimin Wan, Mingzhang Yang, Weiyi Dai, Dongliang Yang, Yanchun Li, Shiyan Li, Soshi Iimura, Shixuan Du, Hideo Hosono, Yanpeng Qi, Jian-gang Guo. 2023-01-09. Superconductivity in an Orbital-reoriented SnAs Square Lattice: a Case Study of Li0.6Sn2As2 and NaSnAs. https://arxiv.org/abs/2301.03240

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