Related papers: Changes in the self-energy and d-wave pairing stre…
The low-energy spin fluctuations in the electron-doped Pr$_{1-x}$LaCe$_{x}$CuO$_{4}$ have been investigated over a wide concentration range of 0.07$\leqslant$ $x$ $\leqslant$0.18 that spans from the antiferromagnetic and non-superconducting…
We investigated the high energy spin excitations in electron-doped $\mathrm{La}_{2-x} \mathrm{Ce}_x \mathrm{CuO}_{4}$, a cuprate superconductor, by resonant inelastic x-ray scattering (RIXS) measurements. Efforts were paid to disentangle…
We have performed a systematic angle-resolved photoemission spectroscopy (ARPES) study of the high-Tc cuprates La2-xSrxCuO4, ranging from the underdoped insulator to the superconductor to the overdoped metal. We have revealed a systematic…
Exploring whether a spin density wave (SDW) is responsible for the charge excitations gap in the high-temperature superconducting cuprates is difficult, since the region of the phase diagram where the magnetic properties are clearly exposed…
The energy spectrum of incommensurate spin fluctuations in superconducting Sr-doped La2CuO4 has been studied by inelastic neutron scattering experiments. An energy gap in the spin excitation spectrum is observed in the superconducting state…
We use resonant inelastic x-ray scattering (RIXS) at the O $K$- and Cu $K$-edges to investigate the doping- and temperature dependence of low-energy plasmon excitations in La$_{2-x}$Sr$_{x}$CuO$_4$. We observe a monotonic increase of the…
We describe here a minimal theory of tight binding electrons moving on the square planar Cu lattice of the hole-doped cuprates and mixed quantum mechanically with pairs of them (Cooper pairs). Superconductivity occurring at the transition…
We report optical reflectivity study on Nd$_{2-x}$Ce$_x$CuO$_4$ over a broad doping range 0$\leq x\leq$0.20. The study reveals a systematic shift of chemical potential with doping. A pronounced peak structure specific to the electron-doped…
We used femtosecond optical pump-probe spectroscopy to study the photoinduced change in reflectivity of thin films of the electron-doped cuprate La$_{2-x}$Ce$_x$CuO$_4$ (LCCO) with dopings of x$=$0.08 (underdoped) and x$=$0.11 (optimally…
We present a single crystal Cu NMR study of the cuprate superconductor La$_{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…
We investigated the Cu-spin correlation in the overdoped regime of the electron-doped high-Tc cuprate thin films of La_2-x_Ce_x_CuO_4_, changing the reduction condition from muon spin relaxation using low-energy muons. The Cu-spin…
We report a detailed inelastic neutron scattering study of the collective magnetic excitations of overdoped superconducting La1.78Sr0.22CuO4 for the energy range 0-160 meV. Our measurements show that overdoping suppresses the strong…
We present angle-resolved photoemission spectroscopy (ARPES) data on moderately underdoped La$_{1.855}$Sr$_{0.145}$CuO$_4$ at temperatures below and above the superconducting transition temperature. Unlike previous studies of this material,…
We investigated the characteristics of the spin fluctuations mediated superconductivity employing the Eliashberg formalism. The effective interaction between electrons was modeled in terms of the spin susceptibility measured by the…
We investigate high-energy spin excitations in hole-doped La$_{2-x}$Ca$_{x}$CuO$_{4-\delta}$ films across a broad Ca doping range $x = 0.05-0.50$ using resonant inelastic x-ray scattering (RIXS). Polarization analysis and incident-photon…
Although spin fluctuations are central to the physics of high-Tc cuprates, their relevance to strange-metal behavior in the overdoped regime remains unclear. Here, we use high magnetic fields to suppress superconductivity and an NMR…
Theories of the origin of superconductivity in cuprates are dependent on an understanding of their normal state which exhibits various competing orders. Transport and thermodynamic measurements on La$_{2-x}$Sr$_x$CuO$_4$ show signatures of…
We study the doping dependence of low frequency spin fluctuations and the zero-temperature superfluid density of La$_{2-x}$Sr$_x$CuO$_4$ using the muon spin relaxation ($\mu$SR) and ac-susceptibility techniques. Superconductivity is found…
We present results of inelastic light scattering experiments on single-crystalline La$_{2-x}$Sr$_{x}$CuO$_4$ in the doping range $0.00 \le x=p \le 0.30$ and Tl$_2$Ba$_2$CuO$_{6+\delta}$ at $p=0.20$ and $p=0.24$. The main emphasis is placed…
We report on the charge kinetics of La_2CuO_4 lightly doped with Li and Sr. Impedance spectroscopy measurements down to 25mK and from 20Hz to 500kHz reveal evidence for low energy charge dynamics, which slow down with decreasing…