Related papers: Closing of the pseudogap in Sr-doped and Nd-codope…
Doped holes in cuprates reside pairwise at lattice-defect O atoms but at different sites in the two cuprate families. In the Sr-doped lanthanum cuprates, the O atoms occupy anion lattice sites and spread due to Coulomb repulsion (relative…
We report the results of Raman scattering experiments on single crystals of La(2-x)Sr(x)CuO(4) that span the range from underdoped (x = 0.10) to overdoped (x =0.22). The spectra are consistent with the existence of a strong anisotropic…
We have performed a temperature-dependent angle-integrated photoemission study of lightly-doped to heavily-overdoped La$_{2-x}$Sr$_{x}$CuO$_4$ and oxygen-doped La$_2$CuO$_{4.10}$. We found that both the magnitude $\Delta$* of the (small)…
X-ray absorption in $\rm Sr_{2}CuO_{4-\delta}-La_{2}CuO_4$ (SCO-LCO) superlattices shows a variable occupation with doping of a hole state different from holes doped for $x \lesssim x_{optimal}$ in bulk $\rm La_{2-x}Sr_{x}CuO_4$ and…
We analyze the hole doping mechanism in Bi_2Sr_{2-x}La_xCuO_{6+\delta} (BSLCO). The singular optimum around x=0.35 is found to be connected with a feedback between the doped CuO_2 layers and its dopant reactant [La^{3+}/Bi^{3+}-O_\delta]…
Inelastic light-scattering spectra of underdoped ${\rm La_{2-x}Sr_xCuO_4}$ (LSCO) single crystals are presented which provide direct evidence of the formation of quasi one-dimensional charged structures in the two-dimensional $\rm CuO_2$…
One of the most widely discussed features of the cuprate high Tc superconductors is the presence of a pseudogap in the normal state. Recent transport and specific heat measurements have revealed an abrupt transition at the pseudogap…
We analyze the results of point-contact measurements in La_{2-x}Sr_{x}CuO_{4} (LSCO) previously reported as a clear evidence of the separation between gap and pseudogap in this copper oxide. Here we show that, in addition to this, the…
Doping $La_2CuO_{4}$ with alkaline-earth, $Ae= Sr,Ba$ generates holes in $La_{2-y-x}Ln_yAe_xCuO_{4}$ ($Ln =$ $Nd,Eu$). A small fraction of the holes, $\check{p} \le $ $0.02$, suppresses 3D-AFM. The rest resides as double holes at $O$ atoms…
A quantum critical point in the single layer, hole-doped cuprate system La$_{1.6-x}$Nd$_{0.4}$Sr$_x$CuO$_4$ (Nd-LSCO), near $x$ = 0.23 has been proposed as an organizing principle for understanding high temperature superconductivity. Our…
The oxygen isotope ($^{16}$O/$^{18}$O) effect (OIE) on the pseudogap (charge-stripe ordering) temperature $T^{\ast}$ is investigated for the cuprate superconductor La$_{2-x}$Sr$_{x}$CuO$_{4}$ as a function of doping $x$ by means of x-ray…
The mysterious pseudogap phase of cuprate superconductors ends at a critical hole doping level p* but the nature of the ground state below p* is still debated. Here, we show that the genuine nature of the magnetic ground state in…
Hole doping of La_{2-x}Ae_xCuO_4 (Ae=Sr,Ba) and La_{2-y-x}Ln_ySr_xCuO_4 (Ln = Nd, Eu; y = 0.4, 0.2) introduces unidirectional charge density waves (CDWs) of incommensurability delta_c(x) in domains of the CuO_2 planes. A periodic structure,…
Comparison with La$_{2-z-x}$Nd$_z$Sr$_x$CuO$_4$ ($z=0, 0.4$) shows that the retrograde doping dependence of charge order in La$_{1.8-x}$Eu$_{0.2}$Sr$_x$CuO$_4$ must be caused by a mechanism transcending the common charge-order generation in…
By considering both the average structural parameters obtained from Rietveld refinement of neutron powder diffraction data, and the local structural parameters obtained from the atomic pair distribution function, we have tested the recent…
We report the results of Raman scattering experiments on single crystals of La(2-x)Sr(x)CuO(4) [La214] as a function of temperature and doping. In underdoped compounds low-energy B1g spectral weight is depleted in association with the…
The Seebeck coefficient $S$ of the cuprate superconductor La$ _{2-x} $Sr$_{x} $CuO$ _{4}$ (LSCO) was measured in magnetic fields large enough to access the normal state at low temperatures, for a range of Sr concentrations from $x = 0.07$…
Quasiparticle tunneling spectra of the electron-doped (n-type) infinite-layer cuprate Sr_{0.9}La_{0.1}CuO_2 reveal characteristics that counter a number of common phenomena in the hole-doped (p-type) cuprates. The optimally doped…
We have investigated the doping and temperature dependences of the pseudogap/superconducting gap in the single-layer cuprate La$_{2-x}$Sr$_x$CuO$_4$ by angle-resolved photoemission spectroscopy. The results clearly exhibit two distinct…
We present a detailed room temperature x-ray powder diffraction study on La2-xSrxNiO4+d with 0<=x<=0.12 and 0<=d<=0.13. For x=0.02, 0.04 and 0.06 the oxygen content phase diagrams of the Sr doped samples show a similar sequence of pure…