Coexistence of Multiple Stacking Charge Density Waves in Kagome Superconductor ${\mathrm{CsV}}_3{\mathrm{Sb}}_5$

Abstract

The recently discovered kagome family AV3Sb5 (A = K, Rb, Cs) exhibits rich physical phenomena, including non-trivial topological electronic structure, giant anomalous Hall effect, charge density waves (CDW) and superconductivity. Notably, CDW in AV3Sb5 is evidenced to intertwine with its superconductivity and topology, but its nature remains elusive. Here, we combine x-ray diffraction experiments and density-functional theory calculations to investigate the CDWs in CsV3Sb5 and demonstrate the coexistence of 2 × 2 × 2 and 2 × 2 × 4 CDW stacking phases. Competition between these CDW phases is revealed by tracking the temperature evolution of CDW intensities, which also manifests in different transition temperatures during warming-and cooling-measurements. We also identify a meta-stable quenched state of CsV3Sb5 after fast-cooling process. Our study demonstrates the coexistence of competing CDW stackings in CsV3Sb5, offering new insights in understanding the novel properties of this system.

Universal three-state nematicity and magneto-optical Kerr effect in the charge density waves in AV$_3$Sb$_5$ (A=Cs, Rb, K)

“…The domains we observe are on the order of 100 µm scale, which explains the nematicity observed in transport experiments on macroscopic samples possibly due to unequal population of three domains [54,55]. Our results add strong constrains on interpreting other macroscopic measurements including photo-emission, x-ray and optical spectroscopy [17,26,30,35,36,57,60,61,[63][64][65][66][67].…”

“…??a, because the onset temperature of birefrigence coincides with T CDW in all three compounds. There have been lots of works of proposing different kinds of stacking between CDW layers [26,30,31,35,56,57,[62][63][64][65]. Our results shows that those without two-fold symmetry are not compatible.…”

Loop currents in $A$V$_3$Sb$_5$ kagome metals: multipolar and toroidal magnetic orders

“…X-ray experiments on AV 3 Sb 5 , however, reveal that the charge-order wavevector can also have a finite commensurate z component, resulting in a 2 × 2 × 2 or 2 × 2 × 4 unit cell in the ordered state [41,44]. The precise c-axis modulation depends not only on the alkali-metal atom A, but also on temperature and pressure [31,61,86].…”

Charge density wave order and fluctuations above T$_{CDW}$ and below superconducting T$_c$ in the kagome metal CsV$_{3}$Sb$_{5}$

“…Moreover, a recent x-ray study by Stahl and collaborators has reported a measurement of the order parameter of several CDW Bragg intensities, suggesting a 2 × 2 × 2 superstructure below 60 K, with a transition to 2 × 2 × 4 above 60 K and below 94 K [16]. A successive high-resolution x-ray work found different results below 60 K and claimed the coexistence of 2 × 2 × 2 and 2×2×4 CDW stacking phases which compete each other [22]. Another recent work combined high-resolution x-ray diffraction, scanning tunneling microscopy and scanning transmission electron microscopy and suggested that the distinct 1 × 4 phase emerges uniquely on the surface [23].…”