Reemergence of high-Tc superconductivity in the (Li1-xFe x )OHFe1-ySe under high pressure

J P Sun; P Shahi; H X Zhou; Y L Huang; K Y Chen; B S Wang; S L Ni; N N Li; K Zhang; W G Yang; Y Uwatoko; G Xing; J Sun; D J Singh; K Jin; F Zhou; G M Zhang; X L Dong; Z X Zhao; J-G Cheng

doi:10.1038/s41467-018-02843-7

Reemergence of high-T_c superconductivity in the (Li_1-xFe _x )OHFe_1-ySe under high pressure

Nat Commun. 2018 Jan 25;9(1):380. doi: 10.1038/s41467-018-02843-7.

Authors

J P Sun^{1

2}, P Shahi^{1

2}, H X Zhou^{1

2}, Y L Huang^{1

2}, K Y Chen^{1

2}, B S Wang^{1

2}, S L Ni^{1

2}, N N Li³, K Zhang³, W G Yang^{3

4}, Y Uwatoko⁵, G Xing^{6

7}, J Sun⁶, D J Singh⁶, K Jin^{1

2}, F Zhou^{1

2}, G M Zhang⁸, X L Dong^{9

10}, Z X Zhao^{1

2}, J-G Cheng^{11

12}

Affiliations

¹ Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.
² School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100190, China.
³ Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai, 201203, China.
⁴ High Pressure Synergetic Consortium (HPSynC), Geophysical Laboratory, Carnegie Institution of Washington, 9700 S Cass Avenue, Argonne, IL, 60439, USA.
⁵ The Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba, 277-8581, Japan.
⁶ Department of Physics and Astronomy, University of Missouri, Columbia, MO, 65211-7010, USA.
⁷ College of Materials Science and Engineering and Key Laboratory of Automobile Materials of MOE, Jilin University, Changchun, 130012, China.
⁸ State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing, 100084, China.
⁹ Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China. dong@iphy.ac.cn.
¹⁰ School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100190, China. dong@iphy.ac.cn.
¹¹ Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China. jgcheng@iphy.ac.cn.
¹² School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100190, China. jgcheng@iphy.ac.cn.

Abstract

In order to elucidate pressure-induced second superconducting phase (SC-II) in A _x Fe_2-ySe₂ (A = K, Rb, Cs, and Tl) having an intrinsic phase separation, we perform a detailed high-pressure magnetotransport study on the isoelectronic, phase-pure (Li_1-xFe _x )OHFe_1-ySe single crystals. Here we show that its ambient-pressure superconducting phase (SC-I) with a critical temperature T_c ≈ 40 K is suppressed gradually to below 2 K and an SC-II phase emerges above P_c ≈ 5 GPa with T_c increasing progressively to above 50 K up to 12.5 GPa. Our high-precision resistivity data uncover a sharp transition of the normal state from Fermi liquid for SC-I to non-Fermi liquid for SC-II phase. In addition, the reemergence of high-T_c SC-II is found to accompany with a concurrent enhancement of electron carrier density. Without structural transition below 10 GPa, the observed SC-II with enhanced carrier density should be ascribed to an electronic origin presumably associated with pressure-induced Fermi surface reconstruction.

Publication types

Research Support, Non-U.S. Gov't