T. P. Croft, C. Lester, M. S. Senn, A. Bombardi, and S. M. Hayden, Phys. Rev. B 89 (2014), 224513
We report hard (14 keV) x-ray diffraction measurements on three compositions (x=0.11,0.12,0.13) of the high-temperature superconductor La 2−x Sr x CuO 4 . All samples show charge density wave (CDW) order with onset temperatures in the range 51–80 K and ordering wave vectors close to (0.23,0,0.5). The CDW is strongest with the longest in-plane correlation length near 1/8 doping. On entering the superconducting state the CDW is suppressed, demonstrating the strong competition between the charge order and superconductivity. CDW order coexists with incommensurate magnetic order and the wave vectors of the two modulations have the simple relationship δ charge =2δ spin . The intensity of the CDW Bragg peak tracks the intensity of the low-energy (quasielastic) spin fluctuations. We present a phase diagram of La 2−x Sr x CuO 4 including the pseudogap phase, CDW, and magnetic order.
