Gap distribution in overdoped La2−xSrxCuO4 observed by scanning tunneling spectroscopy

Distinctive Features of Metal-Insulator Transitions, Multiscale Phase Separation, and Related Effects in Hole-Doped Cuprates

“…Here, it is natural to believe that the density of defect centers D decreases with increasing the doping (i.e. in the metallic state), because the lightly doped cuprates are much more inhomogeneous in comparison with the optimally doped cuprates, as observed in experiments [58]. Further, we took into account that the magnitude of B varies from 0.0003 eV to 0.014 eV for ∞ = 3.5-4.5 and = 0.10-0.12 [54].…”

“…The CDW puddles, like the vapor bubbles in boiling water, as seen by this Xray diffraction [16], are very similar to the deformation clouds of polarons. The lightly doped and underdoped cuprates are inhomogeneous systems (where the dopants and charge carriers are distributed inhomogeneously), and they are more inhomogeneous than optimally doped cuprates [58]. One can assume that the charge carriers (i.e., hole polarons) in these systems segregate into carrier-rich and carrier-poor regions as a result of their specific ordering.…”

“…Many experiments (see Ref. [54,58]) testify to the segregation of charge carriers in inhomogeneous holedoped cuprates into carrier-rich and carrier-poor regions. We imagine this physically as follows.…”

Carrier localization, Anderson transitions and stripe formation in hole-doped cuprates

“…In reality, there are important unexplained differences between the MITs observed in lightly doped [1,2,3], underdoped [4,5,6] and optimally doped [7] cuprates. Another unresolved issue in the physics of high-T c cuprates is the role of the electronic inhomogeneity and charge ordering in the phase separation in the form of alternating dynamic and static stripes [8,9,10,11,12], which is intimately related to carrier localization, MITs and superconductivity in these materials. Our main purpose is to understand the possible microscopic mechanisms leading to the carrier localization, MITs, stripe formation and suppression of superconductivity and to propose a unified theoretical description of these interrelated phenomena in the cuprates.…”

Pseudogap formation and unusual quasiparticle tunneling in cuprate superconductors: Polaronic and multiple-gap effects on the tunneling spectra

“…-One can expect that the electronic inhomogeneity in HTSC may produce regions with a distribution of gap amplitudes (∆(i) and ∆ p (i)) and variation in the local DOS. Recent STM and STS experiments on Bi-2212 and other high-T c systems indicate that the gap inhomogeneities commonly exist in these materials regardless of doping level [22][23][24]37]. Therefore, in order to reproduce the main features of the tunneling spectra of high-T c cuprates, we have to consider the multi-gap case and the multi-channel tunneling processes, which contribute to the total tunneling current.…”