Discovery of conjoined charge density waves in the kagome superconductor CsV3Sb5
Haoxiang Li, G. Fabbris, A. H. Said, Jianping Sun, Yu‐Xiao Jiang, Jia‐Xin Yin, Yun‐Yi Pai, Sangmoon Yoon, Andrew R. Lupini, C. S. Nelson, Q. W. Yin, Chunsheng Gong, Z. J. Tu, Hechang Lei, Jinguang Cheng, M. Zahid Hasan, Ziqiang Wang, Binghai Yan, Ronny Thomale, Ho Nyung Lee, Hu Miao
Abstract
Abstract The electronic instabilities in CsV 3 Sb 5 are believed to originate from the V 3 d -electrons on the kagome plane, however the role of Sb 5 p -electrons for 3-dimensional orders is largely unexplored. Here, using resonant tender X-ray scattering and high-pressure X-ray scattering, we report a rare realization of conjoined charge density waves (CDWs) in CsV 3 Sb 5 , where a 2 × 2 × 1 CDW in the kagome sublattice and a Sb 5 p -electron assisted 2 × 2 × 2 CDW coexist. At ambient pressure, we discover a resonant enhancement on Sb L 1 -edge (2 s →5 p ) at the 2 × 2 × 2 CDW wavevectors. The resonance, however, is absent at the 2 × 2 × 1 CDW wavevectors. Applying hydrostatic pressure, CDW transition temperatures are separated, where the 2 × 2 × 2 CDW emerges 4 K above the 2 × 2 × 1 CDW at 1 GPa. These observations demonstrate that symmetry-breaking phases in CsV 3 Sb 5 go beyond the minimal framework of kagome electronic bands near van Hove filling.