Electronic structure of the ingredient planes of cuprate superconductor Bi2Sr2CuO6+δ: a comparison study with Bi2Sr2CaCu2O8+δ

Abstract

By means of low-temperature scanning tunneling microscopy, we report on the electronic structures of BiO and SrO planes of Bi2Sr2CuO6+δ (Bi-2201) superconductor prepared by argon-ion bombardment and annealing. Depending on post annealing conditions, the BiO planes exhibit either pseudogap (PG) with sharp coherence peaks and an anomalously large gap of 49 meV or van Hove singularity (VHS) near the Fermi level, while the SrO is always characteristic of a PG-like feature. This contrasts with Bi2Sr2CaCu2O8+δ (Bi-2212) superconductor where VHS occurs solely on the SrO plane. We disclose the interstitial oxygen dopants (δ in the formulas) as a primary cause for the occurrence of VHS, which are located dominantly around the BiO and SrO planes, respectively, in Bi-2201 and Bi-2212. This is supported by the contrasting structural buckling amplitude of BiO and SrO planes in the two superconductors. Our findings provide solid evidence for the irrelevance of PG to the superconductivity in the two superconductors, as well as insights into why Bi-2212 can achieve a higher superconducting transition temperature than Bi-2201, and by implication, the mechanism of cuprate superconductivity.

5 pages, 4 figures

References in corpus (13)

• Scanning tunneling spectroscopy of high-temperature superconductors
• Visualizing pair formation on the atomic scale in the high-Tc superconductor Bi2Sr2CaCu2O8+d
• Fermi Arcs in a Doped Pseudospin-1/2 Heisenberg Antiferromagnet
• Observation of a $d$-wave gap in electron-doped Sr${}_2$IrO${}_4$
• Imaging the impact on cuprate superconductivity of varying the inter-atomic distances within individual crystal unit-cells
• An explanation for a universality of transition temperatures in families of copper oxide superconductors
• Composite-Fermion Theory for Pseudogap, Fermi Arc, Hole Pocket, and Non-Fermi-Liquid of Underdoped Cuprate Superconductors
• First direct observation of the Van Hove singularity in the tunneling spectra of cuprates
• Enhancement of the superconducting critical temperature in Bi${}_2$Sr${}_2$CaCu${}_2$O${}_{8+\delta }$ by controlling disorder outside CuO${}_2$ planes
• Correlating off-stoichiometric doping with nanoscale electronic disorder and quasiparticle interference pattern in high-$T_c$ superconductor Bi${}_2$Sr${}_2$CaCu${}_2$O${}_{8+\delta }$
• Mapping the Electronic Structure of Each Ingredient Oxide Layer of High-$T_{\text{c}}$ Cuprate Superconductor Bi2Sr2CaCu2O8+δ
• Nanoscale interplay of strain and doping in a high-temperature superconductor
• Itinerant effects and enhanced magnetic interactions in Bi-based multilayer cuprates

Cited by in corpus (5)

• Nodeless pairing in superconducting copper-oxide monolayer films on Bi2Sr2CaCu2O8+δ
• Atomic Visualization of Copper Oxide Structure in Infinite-Layer Cuprate SrCuO2
• Possible Nodeless Superconducting Gaps in Bi${}_2$Sr${}_2$CaCu${}_2$O${}_{8+\delta }$ and YBa${}_2$Cu${}_3$O${}_{7-x}$ Revealed by Cross-Sectional Scanning Tunneling Spectroscopy
• Molecular beam epitaxy growth and surface structure of Sr1-xNdxCuO2 cuprate films
• Electronic inhomogeneity and band structure on superstructural CuO2 planes of infinite-layer Sr0.94La0.06CuO2+y films