Charge stripe order near the surface of 12-percent doped La2−xSrxCuO4

Abstract

A collective order of spin and charge degrees of freedom into stripes has been predicted to be a possible ground state of hole-doped Cuo 2 planes, which are the building blocks of hightemperature superconductors. In fact, stripe-like spin and charge order has been observed in various layered cuprate systems. For the prototypical high-temperature superconductor La 2 − x sr x Cuo 4 , no charge-stripe signal has been found so far, but several indications for a proximity to their formation. Here we report the observation of a pronounced charge-stripe signal in the near surface region of 12-percent doped La 2 − x sr x Cuo 4 . We conclude that this compound is sufficiently close to charge stripe formation that small perturbations or reduced dimensionality near the surface can stabilize this order. our finding of different phases in the bulk and near the surface of La 2 − x sr x Cuo 4 should be relevant for the interpretation of data from surface-sensitive probes, which are widely used for La 2 − x sr x Cuo 4 and similar systems.

Fluctuating Charge Order: A Universal Phenomenon in Unconventional Superconductivity?

“…Recent experiments in cuprates have revealed ample evidence for incommensurate charge modulations with wavevectors oriented along the crystalline axes, i.e., at 45˝off the SDW vector as well [8,[44][45][46][47][48][49][50][51][52][53][54]. A theoretical investigation examining a multiorbital model of cuprates finds support for such an axial charge order [46] in contrast to previous calculations, which reported wave vectors along the Brillouin zone diagonal.…”

Reconciliation of local and long-range tilt correlations in underdopedLa2−xBaxCuO4(0≤xBožin1, Zhong2, Knox3 et al. 2015Phys. Rev. B297190View full textAdd to dashboardCite

“…The CDW order in YBa 2 Cu 3 O 6+d appears at temperatures as high as ∼ 150 K in a lattice with OI order present to above room temperature. Finally, we note that charge-stripe order has recently been detected by x-ray diffraction in La 2−x Sr x CuO 4 with x ∼ 0.12 [73][74][75][76], confirming an earlier identification by nuclear magnetic resonance [77]. This result is somewhat surprising, as the average structure of La 2−x Sr x CuO 4 is LTO (although electron diffraction studies have indicated LTT-like regions at LTO twin boundaries for x = 0.12 [78] and LTLO order for x = 0.115 [79]).…”

Charge density wave fluctuations inLa2−xSrxCuO4and their competition

“…There have been three recent reports [26][27][28] of x-ray studies of the CDW in La 1.88 Sr 0.12 CuO 4 , one of the compositions studied here, in the last two years. These studies used resonant and non-resonant diffraction techniques with x-ray energies from 529 eV to 100 keV.…”