论文标题
Kagome超导体CSV3SB5中的连接电荷密度波
Conjoined Charge Density Waves in the Kagome Superconductor CsV3Sb5
论文作者
论文摘要
新颖的晶格几何形状和自发对称性的状态之间的复杂相互作用是当代量子材料研究的最前沿。最近,在kagome金属CSV3SB5中观察非常规电荷和配对密度波带来了一个新的展示柜,以进行相互交织的顺序。尽管普遍认为CSV3SB5中的电子不稳定性源自位于2维的Kagome Sublattice上的V 3D电子,但尚未理解SB 5P利电子对3维订单的关键作用。在这里,使用谐振柔性X射线散射和高压X射线散射,我们报告了CSV3SB5中罕见的相连电荷密度波(CDW)的实现。在环境压力下,我们在2 $ \ times $ 2 $ \ times $ 2 $ 2 CDW WaveVectors上发现了SB L1边缘(2S-5P)的共振增强。然而,共振的情况下是2 $ \ times $ 2 cdw WaveVectors。在施加静水压力时,我们发现CDW过渡温度分开,其中2 $ \ times $ 2 $ \ times $ 2 cdw出现在1GPA时2 $ \ times $ 2 cdw以上。我们的结果确定了2 $ \ times $ 2 CDW的共存和5P-电子辅助2 $ \ times $ 2 $ \ times $ \ times $ 2 $ 2 cdw in CSV3SB5。在压力下,相连的CDW的演变表明电子和语音波动对于双圆顶超导性的关节重要性。
The intricate interplay between novel lattice geometry and spontaneous symmetry-breaking states is at the forefront of contemporary research on quantum materials. Recently, the observation of unconventional charge and pairing density waves in a kagome metal CsV3Sb5 brings out a new showcase for intertwined orders. While electronic instabilities in CsV3Sb5 are widely believed to originate from the V 3d-electrons residing on the 2-dimensional kagome sublattice, the pivotal role of Sb 5p-electrons for 3-dimensional orders is yet to be understood. Here, using resonant tender x-ray scattering and high-pressure X-ray scattering, we report a rare realization of conjoined charge density waves (CDW) in CsV3Sb5. At ambient pressure, we discover a resonant enhancement at Sb L1-edge (2s-5p) at the 2$\times$2$\times$2 CDW wavevectors. The resonance, however, is absent at the 2$\times$2 CDW wavevectors. Applying hydrostatic pressure, we find the CDW transition temperatures to separate, where the 2$\times$2$\times$2 CDW emerges 4 K above the 2$\times$2 CDW at 1GPa. Our results establish the coexistence of the 2$\times$2 CDW and the 5p-electron assisted 2$\times$2$\times$2 CDW in CsV3Sb5. The evolution of the conjoined CDWs under pressure suggests the joint importance of electronic and phononic fluctuations for the double dome superconductivity.