Guangyang Dai, Yating Jia, Bo Gao, Yi Peng, Jianfa Zhao, Yanming Ma, Changfeng Chen, Jinlong Zhu, Quan Li, Runze Yu, Changqing Jin
{"title":"Pressure-induced superconductivity in the nonsymmorphic topological insulator KHgAs","authors":"Guangyang Dai, Yating Jia, Bo Gao, Yi Peng, Jianfa Zhao, Yanming Ma, Changfeng Chen, Jinlong Zhu, Quan Li, Runze Yu, Changqing Jin","doi":"10.1038/s41427-023-00496-7","DOIUrl":null,"url":null,"abstract":"Abstract 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 ~16 and 20 GPa, followed by the appearance of superconductivity with a T c of ~3.5 K at approximately 21 GPa. The superconducting transition temperature was enhanced to a maximum of ~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.","PeriodicalId":19382,"journal":{"name":"Npg Asia Materials","volume":null,"pages":null},"PeriodicalIF":8.6000,"publicationDate":"2023-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Npg Asia Materials","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1038/s41427-023-00496-7","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Abstract 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 ~16 and 20 GPa, followed by the appearance of superconductivity with a T c of ~3.5 K at approximately 21 GPa. The superconducting transition temperature was enhanced to a maximum of ~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.
期刊介绍:
NPG Asia Materials is an open access, international journal that publishes peer-reviewed review and primary research articles in the field of materials sciences. The journal has a global outlook and reach, with a base in the Asia-Pacific region to reflect the significant and growing output of materials research from this area. The target audience for NPG Asia Materials is scientists and researchers involved in materials research, covering a wide range of disciplines including physical and chemical sciences, biotechnology, and nanotechnology. The journal particularly welcomes high-quality articles from rapidly advancing areas that bridge the gap between materials science and engineering, as well as the classical disciplines of physics, chemistry, and biology. NPG Asia Materials is abstracted/indexed in Journal Citation Reports/Science Edition Web of Knowledge, Google Scholar, Chemical Abstract Services, Scopus, Ulrichsweb (ProQuest), and Scirus.