Unidirectional electron–phonon coupling in the nematic state of a kagome superconductor
- Resource Type
- Article
- Authors
- Wu, Ping; Tu, Yubing; Wang, Zhuying; Yu, Shuikang; Li, Hongyu; Ma, Wanru; Liang, Zuowei; Zhang, Yunmei; Zhang, Xuechen; Li, Zeyu; Yang, Ye; Qiao, Zhenhua; Ying, Jianjun; Wu, Tao; Shan, Lei; Xiang, Ziji; Wang, Zhenyu; Chen, Xianhui
- Source
- Nature Physics; 20230101, Issue: Preprints p1-7, 7p
- Subject
- Language
- ISSN
- 17452473; 17452481
Electronic nematicity has been commonly observed in juxtaposition with unconventional superconductivity. Understanding the nature of the nematic state and its consequences for the electronic band structure and superconductivity has therefore become a key issue in condensed matter physics. Here we visualize the organization of the interacting quasiparticles in the nematic state of the kagome superconductor CsV3−xTixSb5using scanning tunnelling microscopy. Two-fold symmetric quasiparticle scattering interference of the vanadium kagome bands emerges below the bulk nematic transition temperature deep inside the charge density wave phase. We find that electron–phonon coupling alters the self-energy of the electrons and renormalizes the Fermi velocity of the in-plane vanadium bands only along the symmetry-breaking direction, making the low-energy dispersion and electron dynamics highly non-equivalent along the three lattice directions. The anti-correlation between the nematic transition temperature and the superconducting transition temperature with Ti substitution suggests a possible competition between superconductivity and electronic nematicity, with principal superconducting gaps opening on the same vanadium bands once the nematic state is totally suppressed. This provides a platform for modelling electronic nematicity in systems where electron correlations and lattice degree of freedom act together.