Pressure-induced superconductivity in the nonsymmorphic topological insulator KHgAs

Dai, Guangyang1,2; Jia, Yating1; Gao, Bo3,4; Peng, Yi1,5; Zhao, Jianfa1; Ma, Yanming3,4; Chen, Changfeng6; Zhu, Jinlong2; Li, Quan3,4; Yu, Runze1,7; Jin, Changqing1,5,8

2023-10-06

10.1038/s41427-023-00496-7

NPG ASIA MATERIALS   Impact Factor & Quartile

1884-4049

1884-4057

Recently, topological insulators (TIs) KHgX (X = As, Sb, Bi) with hourglass-shaped dispersion have attracted great interest. Different from the TIs protected by either time-reversal or mirror crystal symmorphic symmetry tested in previous experiments, these materials were proposed as the first material class whose band topology relies on nonsymmorphic symmetries. As a result, KHgX shows many exotic properties, such as hourglass-shaped electronic channels and three-dimensional doubled quantum spin Hall effects. To date, high-pressure experimental studies on these nonsymmorphic TIs are minimal. Here, we carried out high-pressure electrical measurements up to 55 GPa, together with high-pressure X-ray diffraction measurements and high-pressure structure prediction on KHgAs. We found a pressure-induced semiconductor-metal transition between similar to 16 and 20 GPa, followed by the appearance of superconductivity with a T-c of similar to 3.5 K at approximately 21 GPa. The superconducting transition temperature was enhanced to a maximum of similar to 6.6 K at 31.8 GPa and then slowly decreased until 55 GPa. Furthermore, three high-pressure phases within 55 GPa were observed, and their crystal structures were established. Our results showed the high-pressure phase diagram of KHgAs and determined the pressure-induced superconductivity in nonsymmorphic TIs. Thus, our study can be used to facilitate further research on superconductivity and topologically nontrivial features protected by nonsymmorphic symmetries.

SCI

English

Corresponding

National Science Foundation["2022YFA1403800","2018YFA0305700","11921004","U2032220","T2325013","52288102","52090024","12034009"] ; Ministry of Science and Technology of China[2202059]

Materials Science

Materials Science, Multidisciplinary

WOS:001078964100001

NATURE PORTFOLIO

Web of Science

1.Chinese Acad Sci, Inst Phys, Beijing Natl Lab Condensed Matter Phys, Beijing 100190, Peoples R China
2.Southern Univ Sci & Technol, Dept Phys, Shenzhen 518055, Peoples R China
3.Jilin Univ, Coll Phys, State Key Lab Superhard Mat, Minist Educ, Changchun 130012, Peoples R China
4.Jilin Univ, Coll Phys, Key Lab Mat Simulat Methods & Software, Minist Educ, Changchun 130012, Peoples R China
5.Univ Chinese Acad Sci, Sch Phys Sci, Beijing 100190, Peoples R China
6.Univ Nevada, Dept Phys & Astron, Las Vegas, NV 89154 USA
7.Ctr High Pressure Sci & Technol Adv Res HPSTAR, Beijing 100094, Peoples R China
8.Songshan Lake Mat Lab, Dongguan 523808, Peoples R China

Dai, Guangyang,Jia, Yating,Gao, Bo,et al. Pressure-induced superconductivity in the nonsymmorphic topological insulator KHgAs[J]. NPG ASIA MATERIALS,2023,15(1).

Dai, Guangyang.,Jia, Yating.,Gao, Bo.,Peng, Yi.,Zhao, Jianfa.,...&Jin, Changqing.(2023).Pressure-induced superconductivity in the nonsymmorphic topological insulator KHgAs.NPG ASIA MATERIALS,15(1).

Dai, Guangyang,et al."Pressure-induced superconductivity in the nonsymmorphic topological insulator KHgAs".NPG ASIA MATERIALS 15.1(2023).