Related papers: Doping Evolution of the Underlying Fermi Surface i…
We present a single crystal Cu NMR study of the cuprate superconductor La$_{2-x}$Sr$_{x}$CuO$_4$ with hole doping levels between $x=2$\% and $8$\%. Measurements with short spin echo times enable us to systematically study the local…
Employing the four-band tight-binding model we study theoretically the doping dependence of the spin response in the normal state of novel Fe-based pnictide superconductors. We show that the commensurate spin density wave (SDW) transition…
We use angle-resolved photoemission spectroscopy to study the doping evolution of infinite-layer Sr$_{1-x}$La$_{x}$CuO$_{2}$ thin films grown by molecular-beam epitaxy. At low doping, the material exhibits a dispersive lower Hubbard band…
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…
The Cu substitution effect on the superconductivity of LiFeAs has been studied in comparison with Co/Ni substitution. It is found that the shrinking rate of the lattice parameter c for Cu substitution is much smaller than that of Co/Ni…
Measured transport properties of three representative cuprates are reproduced within the paradigm of two electron subsystems, itinerant and localized. The localized subsystem evolves continuously from the Cu 3d$^9$ hole at half-filling and…
The London penetration depth was measured in single crystals of self-doped Na$_{1-\delta}$FeAs (from under - to optimal - doping, $T_c$ from 14 to 27 K) and electron-doped Na(Fe$_{1-x}$Co$_{x}$)As with $x$ ranging from undoped, $x=0$ to…
Hall coefficient $R_H$ and thermoelectric power TEP are studied systematically in the single crystals $Nd_{2-x}Ce_xCuO_{4+\delta}$ (NCCO) with different x from underdoped to overdoped regime. With increasing doping level, both $R_H$ and TEP…
The anelastic spectrum of La{2-x}Sr{x}CuO{4} (x = 0, 0.008, 0.019, 0.032) has been measured down to 1.5 K, in order to see the effect of doping on the intrinsic lattice fluctuations already found in stoichiometric La{2}CuO{4}, and…
We discuss doping dependencies of the electronic structure and Fermi surface of the monolayer Tl$_{2-x}$Cu$_x$Ba$_2$CuO$_{6+\delta}$ (Tl2201). The TlO bands are found to be particularly sensitive to doping in that these bands rapidly move…
We present an angle resolved photoemission (ARPES) doping dependence study of the n-type cuprate superconductor Nd_2-xCe_xCuO_4, from the half-filled Mott-insulator to the T_c=24K superconductor. In Nd2CuO4, we reveal the charge-transfer…
We report direction-dependent susceptibility and resistivity measurements on La$_{2-x}$Sr$_{x}$CuO$_{4}$ single crystals. These crystals have rectangular needle-like shapes with the crystallographic "c" direction parallel or perpendicular…
We present in-plane optical study on Tl$_{2}$Ba$_{2}$CuO$_{6+\delta}$ single crystals with substantially different $T_c$. The study reveals that the overdoping does not lead to a further increase of the carrier density but a decrease of…
We use time-of-flight (ToF) inelastic neutron scattering (INS) spectroscopy to investigate the doping dependence of magnetic excitations across the phase diagram of NaFe$_{1-x}$Co$_x$As with $x=0, 0.0175, 0.0215, 0.05,$ and $0.11$. The…
We report a study of magnetic, thermal, and transport properties of La(3+) substituted Sr2RuO4, performed in order to investigate the effects of additional electron doping in this correlated metal. A gradual enhancement of the electronic…
The electrical resistivity (Rxx) and Hall resistivity (Rxy) of LaFeAsO1-xFx have been measured over a wide fluorine doping range 0 =< x =< 0.14 using 60 T pulsed magnets. While the superconducting phase diagram (Tc, x) displays the classic…
We have studied the chemical potential shift in La$_{2-x}$Sr$_x$NiO$_4$ and the charge ordering transition in La$_{1.67}$Sr$_{0.33}$NiO$_4$ by photoemission spectroscopy. The result shows a large ($\sim$ 1 eV/hole) downward shift of the…
We have calculated the Raman B$_{1g}$ and B$_{2g}$ spectra as a function of temperature, as well as doping, for the underdoped cuprates, using a model based on the resonating valence-bond spin-liquid. We discuss changes in intensity and…
The real part of the optical in-plane conductivity of p-- and n--type cuprates thin films at various doping levels was deduced from highly accurate reflectivity measurements. We present here a comprehensive set of optical spectral weight…
First principles band-structure calculations for large supercells of Ba$_{2}$CuO$_{4-\delta}$ and La$_{2}$CuO$_{4-\delta}$ with different distributions and concentrations of oxygen vacancies show that the effective doping on copper sites…