X-Ray Diffraction Observations of a Charge-Density-Wave Order in Superconducting Ortho-IIYBa2Cu3O6.54Single Crystals in Zero Magnetic Field

Abstract

X-ray diffraction measurements show that the high-temperature superconductor YBa2Cu3O6.54, with ortho-II oxygen order, has charge density wave order (CDW) in the absence of an applied magnetic field. The dominant wavevector of the CDW is qCDW = (0, 0.328(2), 0.5), with the in-plane component parallel to the b-axis (chain direction). It has a similar incommensurability to that observed in ortho-VIII and ortho-III samples, which have different dopings and oxygen orderings. Our results for ortho-II contrast with recent high-field NMR measurements, which suggest a commensurate wavevector along the a-axis. We discuss the relationship between spin and charge correlations in YBa2Cu3Oy, and recent high-field quantum oscillation, NMR and ultrasound experiments.

Ideal charge-density-wave order in the high-field state of superconducting YBCO

“…1C). Similar to the case of YBCO ortho-VIII (13), the field-induced 3D CDW exhibits the same q-value as that of the zero-field quasi-2D CDW but with an integer rather than a half-integer l -value (8,15). Note that the quasi-2D CDW still exists at this field (SI Appendix, Fig.…”

“…Indeed, X-ray scattering shows that the onset of the quasi-2D order is gradual without a sharp transition (7-17), consistent with the influence of quenched disorder on an incommensurate CDW (19-21). Furthermore, whereas Y-based and La-based cuprates exhibit a clear competition between CDW and superconductivity (7,8,(12)(13)(14)(15), such competition is not apparent in the families of Bi-based and Hg-based cuprate compounds (9-11)-a discrepancy that probably reflects different degrees of quenched disorder among cuprate families.Recently, a CDW with significantly longer correlation lengths was observed in superconducting YBCO (Fig. 1B) via X-ray scattering at high magnetic fields (13,14).…”

“…high-temperature superconductors | charge-density-wave order | high magnetic field X-ray scattering | vestigial nematic order | competing order C harge-density-wave (CDW) order has been found to exist universally in the hole-doped superconducting cuprates (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18), and the common characteristics at zero magnetic field include bidirectionality, quasi-2D and short-ranged correlations (7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17). More specifically, the CDW diffraction patterns are found in both directions of Cu-O bonds in the CuO2 plane (Fig.…”

“…More specifically, the CDW diffraction patterns are found in both directions of Cu-O bonds in the CuO2 plane (Fig. 1A), and the CDW correlation lengths parallel and perpendicular to the planes (i.e., along the a-or b-axes and the c axis) are less than ∼ 20 and ∼ 1 lattice constants, respectively (7)(8)(9)(10)(11)(12)(13)(14)(15)(16), corresponding to a correlation volume of order 10 2 unit cells (UCs). Thus, the properties of the quasi-2D CDW are likely strongly affected by disorder and only indirectly represent the true nature of the underlying CDW correlations.…”

“…Thus, the properties of the quasi-2D CDW are likely strongly affected by disorder and only indirectly represent the true nature of the underlying CDW correlations. Indeed, X-ray scattering shows that the onset of the quasi-2D order is gradual without a sharp transition (7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17), consistent with the influence of quenched disorder on an incommensurate CDW (19)(20)(21). Furthermore, whereas Y-based and La-based cuprates exhibit a clear competition between CDW and superconductivity (7,8,(12)(13)(14)(15), such competition is not apparent in the families of Bi-based and Hg-based cuprate compounds (9-11)-a discrepancy that probably reflects different degrees of quenched disorder among cuprate families.…”