Superconductivity above 200 K discovered in superhydrides of calcium

Zhiwen Li; Xin He; Changling Zhang; Xiancheng Wang; Sijia Zhang; Yating Jia; Shaomin Feng; Ke Lu; Jianfa Zhao; Jun Zhang; Baosen Min; Youwen Long; Richeng Yu; Luhong Wang; Meiyan Ye; Zhanshuo Zhang; Vitali Prakapenka; Stella Chariton; Paul A Ginsberg; Jay Bass; Shuhua Yuan; Haozhe Liu; Changqing Jin

doi:10.1038/s41467-022-30454-w

Superconductivity above 200 K discovered in superhydrides of calcium

Nat Commun. 2022 May 23;13(1):2863. doi: 10.1038/s41467-022-30454-w.

Authors

Zhiwen Li^#^{1

2}, Xin He^#^{1

2

3}, Changling Zhang^#^{1

2}, Xiancheng Wang^{4

5}, Sijia Zhang¹, Yating Jia¹, Shaomin Feng¹, Ke Lu^{1

2}, Jianfa Zhao^{1

2}, Jun Zhang^{1

2}, Baosen Min^{1

2}, Youwen Long^{1

2

3}, Richeng Yu^{1

2}, Luhong Wang⁶, Meiyan Ye⁷, Zhanshuo Zhang⁷, Vitali Prakapenka⁸, Stella Chariton⁸, Paul A Ginsberg⁹, Jay Bass⁹, Shuhua Yuan¹⁰, Haozhe Liu¹⁰, Changqing Jin^{11

12

13}

Affiliations

¹ Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China.
² School of Physical Sciences, University of Chinese Academy of Sciences, 100190, Beijing, China.
³ Songshan Lake Materials Laboratory, 523808, Dongguan, China.
⁴ Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China. Wangxiancheng@iphy.ac.cn.
⁵ School of Physical Sciences, University of Chinese Academy of Sciences, 100190, Beijing, China. Wangxiancheng@iphy.ac.cn.
⁶ Harbin Institute of Technology, 130001, Harbin, China.
⁷ Jilin University, Changchun, China.
⁸ Center for Advanced Radiations Sources, University of Chicago, Chicago, IL, 60637, USA.
⁹ Department of Geology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
¹⁰ Center for High Pressure Science & Technology Advanced Research, 100094, Beijing, China.
¹¹ Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China. Jin@iphy.ac.cn.
¹² School of Physical Sciences, University of Chinese Academy of Sciences, 100190, Beijing, China. Jin@iphy.ac.cn.
¹³ Songshan Lake Materials Laboratory, 523808, Dongguan, China. Jin@iphy.ac.cn.

^# Contributed equally.

Abstract

Searching for superconductivity with T_c near room temperature is of great interest both for fundamental science & many potential applications. Here we report the experimental discovery of superconductivity with maximum critical temperature (T_c) above 210 K in calcium superhydrides, the new alkali earth hydrides experimentally showing superconductivity above 200 K in addition to sulfur hydride & rare-earth hydride system. The materials are synthesized at the synergetic conditions of 160~190 GPa and ~2000 K using diamond anvil cell combined with in-situ laser heating technique. The superconductivity was studied through in-situ high pressure electric conductance measurements in an applied magnetic field for the sample quenched from high temperature while maintained at high pressures. The upper critical field Hc(0) was estimated to be ~268 T while the GL coherent length is ~11 Å. The in-situ synchrotron X-ray diffraction measurements suggest that the synthesized calcium hydrides are primarily composed of CaH₆ while there may also exist other calcium hydrides with different hydrogen contents.