title: Correlation between superconductivity and bond angle of CrAs chain in non-centrosymmetric compounds A2Cr3As3(A = K, Rb).
abstract: Non-centrosymmetric superconductors, whose crystal structure is absent of inversion symmetry, have recently received special attentions due to the expectation of unconventional pairings and exotic physics associated with such pairings. The newly discovered superconductors A2Cr3As3(A = K, Rb), featured by the quasi-one dimensional structure with conducting CrAs chains, belongs to such kind of superconductor. In this study, we are the first to report the finding that superconductivity of A2Cr3As3(A = K, Rb) has a positive correlation with the extent of non-centrosymmetry. Our in-situ high pressure ac susceptibility and synchrotron x-ray diffraction measurements reveal that the larger bond angle of As-Cr-As (defined as α) in the CrAs chains can be taken as a key factor controlling superconductivity. While the smaller bond angle (defined as β) and the distance between the CrAs chains also affect the superconductivity due to their structural connections with the α angle. We find that the larger value of α-β, which is associated with the extent of the non-centrosymmetry of the lattice structure, is in favor of superconductivity. These results are expected to shed a new light on the underlying mechanism of the superconductivity in these Q1D superconductors and also to provide new perspective in understanding other non-centrosymmetric superconductors.
authors.affiliation: Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Yi
authors.affiliation: Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Wu
authors.affiliation: Institute for High Pressure Physics, Russian Academy of Sciences, 142190 Troitsk, Moscow, Russia.
authors.forename: Vladimir A
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authors.lastname: Sidorov
authors.affiliation: Department of Physics, Zhejiang University, Hangzhou 310027, China.
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authors.lastname: Bao
authors.affiliation: Department of Physics, Zhejiang University, Hangzhou 310027, China.
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authors.lastname: Tang
authors.affiliation: Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190, China.
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authors.affiliation: Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190, China.
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authors.lastname: Zhou
authors.affiliation: Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Shan
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authors.lastname: Zhang
authors.affiliation: Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Hang
authors.initials: H
authors.lastname: Li
authors.affiliation: Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Youguo
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authors.lastname: Shi
authors.affiliation: Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Xianxin
authors.initials: X
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authors.affiliation: Shanghai Synchrotron Radiation Facilities, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Shanghai Synchrotron Radiation Facilities, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204, China.
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authors.initials: K
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authors.affiliation: Shanghai Synchrotron Radiation Facilities, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204, China.
authors.forename: Aiguo
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authors.lastname: Li
authors.affiliation: Department of Physics, Zhejiang University, Hangzhou 310027, China.
authors.forename: Guanghan
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authors.lastname: Cao
authors.affiliation: Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190, China.|Collaborative Innovation Center of Quantum Matter, Beijing, 100190, China.
authors.forename: Jiangping
authors.initials: J
authors.lastname: Hu
authors.affiliation: Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190, China.|Collaborative Innovation Center of Quantum Matter, Beijing, 100190, China.
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authors.initials: L
authors.lastname: Sun
authors.affiliation: Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190, China.|Collaborative Innovation Center of Quantum Matter, Beijing, 100190, China.
authors.forename: Zhongxian
authors.initials: Z
authors.lastname: Zhao