Yong Hu, Congcong Le, Yuhang Zhang, Zhen Zhao, Jiali Liu, Junzhang Ma, Nicholas C. Plumb, Milan Radovic, Hui Chen, Andreas P. Schnyder, Xianxin Wu, Xiaoli Dong, Jiangping Hu, Haitao Yang, Hong-Jun Gao, Ming Shi
{"title":"Non-trivial band topology and orbital-selective electronic nematicity in a titanium-based kagome superconductor","authors":"Yong Hu, Congcong Le, Yuhang Zhang, Zhen Zhao, Jiali Liu, Junzhang Ma, Nicholas C. Plumb, Milan Radovic, Hui Chen, Andreas P. Schnyder, Xianxin Wu, Xiaoli Dong, Jiangping Hu, Haitao Yang, Hong-Jun Gao, Ming Shi","doi":"10.1038/s41567-023-02215-z","DOIUrl":null,"url":null,"abstract":"Electronic nematicity that spontaneously breaks rotational symmetry is a generic phenomenon in correlated quantum systems including high-temperature superconductors and the AV3Sb5 (A can be K, Rb or Cs) family of kagome superconductors. However, the underlying mechanism of nematicity in these systems is hard to identify because of its entanglement with other ordered phases. Recently, a family of titanium-based kagome superconductors ATi3Bi5 have been synthesized, where electronic nematicity occurs in the absence of charge order. It provides a platform to study nematicity in its pure form, as well as its interplay with orbital degrees of freedom. Here we reveal the band topology and orbital characters of the multiorbital RbTi3Bi5. We use polarization-dependent angle-resolved photoemission spectroscopy with density functional theory to identify the coexistence of flat bands, type-II Dirac nodal lines and non-trivial topology in this compound. Our study demonstrates the change in orbital character along the Fermi surface contributed by the kagome bands, implying a strong intrinsic interorbital coupling in the Ti-based kagome metals. Furthermore, doping-dependent measurements uncover the orbital-selective features in the kagome bands, which can be explained by d–p hybridization. Hence, interorbital coupling together with d–p hybridization is probably the origin of electronic nematicity in ATi3Bi5. The origin of nematicity in kagome superconductors has been hard to explain due to other entangled phases. Now, the role of orbital hybridization and coupling is revealed to induce electronic nematicity in the kagome superconductor RbTi3Bi5.","PeriodicalId":19100,"journal":{"name":"Nature Physics","volume":null,"pages":null},"PeriodicalIF":17.6000,"publicationDate":"2023-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"9","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Nature Physics","FirstCategoryId":"101","ListUrlMain":"https://www.nature.com/articles/s41567-023-02215-z","RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"PHYSICS, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 9
Abstract
Electronic nematicity that spontaneously breaks rotational symmetry is a generic phenomenon in correlated quantum systems including high-temperature superconductors and the AV3Sb5 (A can be K, Rb or Cs) family of kagome superconductors. However, the underlying mechanism of nematicity in these systems is hard to identify because of its entanglement with other ordered phases. Recently, a family of titanium-based kagome superconductors ATi3Bi5 have been synthesized, where electronic nematicity occurs in the absence of charge order. It provides a platform to study nematicity in its pure form, as well as its interplay with orbital degrees of freedom. Here we reveal the band topology and orbital characters of the multiorbital RbTi3Bi5. We use polarization-dependent angle-resolved photoemission spectroscopy with density functional theory to identify the coexistence of flat bands, type-II Dirac nodal lines and non-trivial topology in this compound. Our study demonstrates the change in orbital character along the Fermi surface contributed by the kagome bands, implying a strong intrinsic interorbital coupling in the Ti-based kagome metals. Furthermore, doping-dependent measurements uncover the orbital-selective features in the kagome bands, which can be explained by d–p hybridization. Hence, interorbital coupling together with d–p hybridization is probably the origin of electronic nematicity in ATi3Bi5. The origin of nematicity in kagome superconductors has been hard to explain due to other entangled phases. Now, the role of orbital hybridization and coupling is revealed to induce electronic nematicity in the kagome superconductor RbTi3Bi5.
期刊介绍:
Nature Physics is dedicated to publishing top-tier original research in physics with a fair and rigorous review process. It provides high visibility and access to a broad readership, maintaining high standards in copy editing and production, ensuring rapid publication, and maintaining independence from academic societies and other vested interests.
The journal presents two main research paper formats: Letters and Articles. Alongside primary research, Nature Physics serves as a central source for valuable information within the physics community through Review Articles, News & Views, Research Highlights covering crucial developments across the physics literature, Commentaries, Book Reviews, and Correspondence.