Related papers: Superconducting Gap and Pseudogap in Bi-2212
We investigate pseudogap phenomena in the 2D electron system. Based on the mode-mode coupling theory of antiferromagnetic (AFM) and $d_{x^2-y^2}$-wave superconducting ($d$SC) fluctuations, single-particle dynamics is analyzed. For the…
We study the anomalous normal state properties of a simple two-dimensional model whose ground state is a d-wave superconductor. Using a self-consistent, conserving formulation, we show that pairing correlations above T_c lead to the…
We report on NMR measurements in underdoped Pb2Sr2(Y,Ca)Cu3O8+d crystals. A pseudogap is observed in the Knight shift and spin-lattice relaxation rate. In contrast to other underdoped compounds, the pseudogap observed in the Knight shift is…
We report on a study of the electromagnetic response of three different families of high-T_c superconductors that in combination allowed us to cover the whole doping range from under- to overdoped. The discussion is focused on the ab-plane…
We study the model high-temperature superconductor HgBa2CuO4+d with electronic Raman scattering and optical ellipsometry over a wide doping range. The resonant Raman condition which enhances the scattering cross section of "two-magnon"…
High-transition-temperature (high-Tc) superconductivity is ubiquitous in the cuprates containing CuO2 planes but each cuprate has its own character. The study of the material dependence of the d-wave superconducting gap (SG) should provide…
In contrast to a complex feature of antinodal state, suffering from competing order(s), the "pure" pairing gap of cuprates is detected in the nodal region, which therefore holds the key to the superconducting mechanism. The pairing gap has…
Scanning tunneling spectroscopy (STS) studies reveal long-range spatial homogeneity and predominantly $d_{x^2-y^2}$-pairing spectral characteristics in under- and optimally doped $\rm YBa_2Cu_3O_{7-\delta}$ superconductors, whereas STS on…
We analyze the single-particle spectra of a bi-layered electron system near a stripe instability and compare the results with ARPES experiments on the Bi2212 cuprate superconductor near optimum doping, addressing also the issue of the…
In a recent article, Alldredge et al. reported tunnelling data obtained at T = 4.2 K by STM in Bi-2212 having different doping levels, p, and a new way to fit the measured differential conductances, g(V), which are linearly proportional to…
The pseudogap state is one of the peculiarities of the cuprate high temperature superconductors. Here we investigate its presence in BaCo$_{x}$Fe$_{2-x}$As$_{2}$, a member of the pnictide family, with temperature dependent scanning…
Scanning Tunneling Spectroscopy on cleaved BSCCO(2212) single crystals reveal inhomogeneities on length-scales of $\sim$30 $\AA$. While most of the surface yields spectra consistent with a d-wave superconductor, small regions show a doubly…
We calculate the c-axis infrared conductivity $\sigma_c(\omega)$ in underdoped cuprate superconductors for spinfluctuation exchange scattering within the CuO$_2$-planes including a phenomenological d-wave pseudogap of amplitude $E_g$. For…
We present the results of directional point-contact spectroscopy in state-of-the-art Mg_{1-x}Al_xB_2 and Mg(B_{1-y}C_{y})_2 single crystals produced at ETH, Zurich. Fitting the conductance curves of our point contacts, that always feature…
In the present work, scanning tunneling microscopy/spectroscopy (STM/STS) measurements were carried out on underdoped $\rm Bi_2Sr_{2-{\it x}}La_{\it x}CuO_{6+\delta}$ and $\rm Bi_2Sr_2CaCu_2O_{8+\delta}$ to clarify the origin of the…
The nature of the pseudogap state, observed above the superconducting transition temperature TC in many high temperature superconductors, is the center of much debate. Recently, this discussion has focused on the number of energy gaps in…
For the mechanism of high-Tc superconductivity in inhomogeneous Bi-2212 superconductors, we demonstrate the intrinsic superconducting gap,GAP_i, and pairing symmetry by using a developed GAP=GAP_i/rho, where GAP is the observed energy gap…
Pseudogap phase in superconductors continues to be an outstanding puzzle that differentiates unconventional superconductors from the conventional ones (BCS-superconductors). Employing high resolution photoemission spectroscopy on a highly…
On the basis of Quantum Monte Carlo simulations of the two-dimensional Hubbard model which cover the doping range from the under- to the over-doped regime, we find that the single-particle spectral weight $A (\vec k,\omega)$ qualitatively…
Measurements of the c-axis resistivity and magnetoresistance have been used to investigate the pseudogap (PG) behavior in Bi_{2+z}Sr_{2-x-z}La_xCuO_y (Bi-2201) crystals at various hole densities. While the PG opening temperature T*…