Related papers: Comment on Visualization of the interplay between …
Recent tunneling observations of a pseudogap in Bi_2Sr_2CaCu_2O_{8+delta} are not necessarily evidence that the pseudogap is associated with superconducting fluctuations. The data are here analyzed as a competition between superconductivity…
In conventional superconductors, a gap exists in the energy absorption spectrum only below the transition temperature (Tc), corresponding to the energy price to pay for breaking a Cooper pair of electrons. In high-Tc cuprate superconductors…
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…
Although nineteen years have passed since the discovery of high temperature superconductivity, there is still no consensus on its physical origin. This is in large part because of a lack of understanding of the state of matter out of which…
The nature of the pseudogap phase of cuprate high-temperature superconductors is a major unsolved problem in condensed matter physics. We studied the commencement of the pseudogap state at temperature T* using three different techniques…
Reproducible scanning tunneling microscope (STM) spectra of $Bi_2Sr_2CaCu_2O_{8+\delta}$ consistently exhibit asymmetric tunneling characteristics, with the higher peak conductance corresponding to a negatively biased sample. We consider…
The main purpose of this brief review is to present a sketch of the mechanism of high-Tc superconductivity based mainly on tunneling measurements in cuprates. In the review, we shall mostly discuss tunneling spectroscopy in Bi2212. Analysis…
The relationship between the pseudogap and superconductivity remains a central puzzle in the physics of cuprates. Hydrostatic pressure provides a clean tuning parameter free from chemical disorder, yet probing the microscopic energy scales…
Understanding of the puzzling phenomenon of high temperature superconductivity requires reliable spectroscopic information about temperature dependence of the bulk electronic density of states. Here I present a comprehensive analysis of…
We have found a quantitative connection between the evolution of the inhomogeneous nanoscale electronic gaps (INSEG) state detected in Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ by scanning tunneling microscopy/spectroscopy (STM/S) and the two…
I present a selection of experimental results on metallic cuprates, both above the superconducting transition temperature $T_c$ (often called the strange metal state) and in the superconducting state. It highlights this still poorly…
A pairing gap and coherence are the two hallmarks of superconductivity. In a classical BCS superconductor they are established simultaneously at Tc. In the cuprates, however, an energy gap (pseudogap) extends above Tc. The origin of this…
Analyses of experimental data in the literature show thresholds that directly imply a coexistent superconductive (SC) and pseudogap (PG) phase that, to our knowledge, has not been previously identified. The data used emphasize the essences…
We report on results of our analysis of published experimental data of the in-plane infrared response of two representative underdoped high-$T_{\mathrm{c}}$ cuprate superconductors, focusing on a characteristic gap feature in the spectra of…
We review the contribution of infrared spectroscopy to the study of the pseudogap in high temperature superconductors. The pseudogap appears as a depression of the frequency dependent conductivity in the c-axis direction and seems to be…
Analysis of the resistivity data recently reported by Kondo et al. [1] for (Bi,Pb)2(Sr,La)2CuO{6-delta} (Bi2201) single-crystals has been performed within our model developed to study pseudogap (PG) in high-Tc superconductors (HTS's). The…
On the basis of the model that was successfully applied to KC8, RbC8, and CsC8 in 1982, we have calculated the superconducting transition temperature Tc for CaC6 and YbC6 to find that the same model reproduces the observed Tc in those…
To address the issue of the pseudogap in the superconducting state of the high temperature superconducting cuprates, we studied the temperature dependent redistribution of the spectral weight in the \textit{c}-axis polarized optical spectra…
When matter undergoes a phase transition from one state to another, usually a change in symmetry is observed, as some of the symmetries exhibited are said to be spontaneously broken. The superconducting phase transition in the underdoped…
In the quest to understand high-temperature superconductivity in copper oxides, a vigorous debate has been focused on the pseudogap - a partial gap that opens over portions of the Fermi surface in the 'normal' state above the bulk critical…