Robustness of the unidirectional stripe order in the kagome superconductor CsV₃Sb₅

Abstract

V-based kagome materials AV3Sb5 (A=K, Rb, Cs) have attracted much attentions due to their novel properties such as unconventional superconductivity, giant anomalous Hall effect, charge density wave (CDW) and pair density wave. Except for the 2a 0×2a 0 CDW (charge density wave with in-plane 2×2 superlattice modulation) in AV3Sb5, an additional 1×4 (4a 0) unidirectional stripe order has been observed at the Sb surface of RbV3Sb5 and CsV3Sb5. However, the stability and electronic nature of the 4a 0 stripe order remains controversial and unclear. Here, by using low-temperature scanning tunneling microscopy/spectroscopy (STM/S), we systematically study the 4a 0 stripe order on the Sb-terminated surface of CsV3Sb5. We find that the 4a 0 stripe order is visible in a large energy range. The STM images with positive and negative bias show contrast inversion, which is the hallmark for the Peierls-type CDW. In addition, below the critical temperature about 60 K, the 4a 0 stripe order keeps unaffected against the topmost Cs atoms, point defects, step edges and magnetic field up to 8 T. Our results provide experimental evidences on the existence of unidirectional CDW in CsV3Sb5.

Superconductivity and unconventional density waves in vanadium-based kagome materials AV3Sb5

“…7(a)-7(c). This special charge order can persist to surface defects and step edge [72] [Fig. 7(d)] and occasionally extend to 5a 0 [Fig.…”

“…(d) Observation of stripe order across the step edge (adapted from Ref. [72]). (e) The Fourier transform signal of stripe order at various temperatures, along different directions and at distinct scanning bias, showing that the non-dispersive and unidirectional stripe order disappears around 60 K (adapted from Ref.…”

Surface-independent CO2 and CO reduction on two-dimensional kagome metal KV3Sb5

“…The above order of surface stability is consistent with that observed in a recent study on CsV 3 Sb 5 . 74 In addition, because KV 3 Sb 5 loses a portion of K when immersed in water (about 8%), 5 the exposed K layer of the surfaces K and Sb2-K may be dissolved. Therefore, we only investigated the catalysis on the exposed Sb2 and VSb1 layers.…”

Band splitting and enhanced charge density wave modulation in Mn-implanted CsV3Sb5

“…8,21 In the CVS system, a typical CDW transition appears at T CDW = 94 K from the transport experiments. However, according to STM and ARPES measurements, 22–24 there are complex charge ordering phenomena hidden in conventional CDW transition, such as 2 × 2 restructure and 1 × 4 unidirectional ordering in the ab plane and CDW along the c -axis. The distortion of in-plane and out-of-plane charge orders leads to symmetry breaking of the lattice, including C 6 rotational symmetry and interlayer inversion symmetry breaking of the lattice, thus disturbing the symmetry protection of surface Dirac states.…”