Scanning Tunneling Spectroscopy ofBi2Sr2CuO6+δ

Abstract

Using scanning tunneling spectroscopy, we investigated the temperature dependence of the quasiparticle density of states of overdoped Bi(2)Sr(2)CuO(6+delta) between 275 mK and 82 K. Below T(c) = 10 K, the spectra show a gap with well-defined coherence peaks at +/-Delta(p) approximately 12 meV, which disappear at T(c). Above T(c), the spectra display a clear pseudogap of the same magnitude, gradually filling up and vanishing at T(*) approximately 68 K. The comparison with Bi(2)Sr(2)CaCu(2)O(8+delta) demonstrates that the pseudogap and the superconducting gap scale with each other, providing strong evidence that they have a common origin.

Evolution of a Pairing-Induced Pseudogap from the Superconducting Gap of(Bi,Pb)2Sr2CuO6

“…There are two different proposals to explain the PG; one is associated with the formation of local incoherent pairs above T c (precursor pairing) [1] and the other is not directly related to the superconductivity and rather competes with superconductivity [2,3,4]. The former is based on the experimental results from angleresolved photoemission spectroscopy (ARPES) [5,6,7] and tunneling spectroscopy [8,9], which demonstrate a smooth evolution of the superconducting (SC) gap into the PG across T c , and the overall d-wave symmetry of PG [10,11]. The latter scenario is based on ARPES [12,13,14,15], tunneling spectroscopy [16], and Raman scattering [17] studies, which reported two different types of energy gaps; a SC gap which opens below T c in the nodal region and an antinodal PG whose magnitude shows a T -independence across T c .…”

Intrinsic tunneling spectroscopy: a look from the inside at HTSC

“…The σ(V ) curves have an inverted parabolic shape, which might indicate the presence of van-Hove singularity close to the Fermi level in slightly OD samples. The behaviour of the SG in UD samples at T → T c is one of the most important and yet controversial issues [12,17]. For UD samples the peak is much weaker than for OD samples even at low T , cf.…”

Spin Polaron-Bipolaron Scenario of Three Gap-Like Energy Scales in Superconducting Cuprates

“…The term pseudogap has been coined to describe this kind of physics. The presence of pseudogap has been established through the measurements of the nuclear magnetic resonance (NMR) [5], the scanning tunneling spectroscopy [6][7][8][9], the analysis of the electronic Raman scattering [10][11][12], through time-resolved optical spectroscopy [13][14][15][16][17][18], and through the ARPES [19][20][21][22][23][24][25]. The observed strong Nernst effect in cuprates has been also attributed to it [26][27][28].…”