Origin of the T${}_c$ enhancement in heterostructure cuprate superconductors

Abstract

Recent experiments on heterostructures composed of two or more films of cuprate superconductors of different oxygen doping levels\cite{Yuli,Gozar} have shown a remarkable T${}_c$ enhancement (up to 50%) relative to single compound films. We provide here a simple explanation of the enhancement which arises naturally from a collection of experimental works. We show that the enhancement could be caused by a structural change in the lattice, namely an increase in the distance of the apical oxygen from the copper-oxygen plane. This increase modifies the effective off-site interaction in the plane which in turn enhances the d-wave superconductivity order parameter. To illustrate this point we study the extended Hubbard model using the fluctuation exchange approximation.

References in corpus (8)

• High-temperature interface superconductivity between metallic and insulating cuprates
• Diamagnetism and Cooper pairing above $T_c$ in cuprates
• Apical oxygens and correlation strength in electron and hole doped copper oxides
• A route to high temperature superconductivity in composite systems
• Enhancement of the superconducting transition temperature in La2-xSrxCuO4 bilayers: Role of pairing and phase stiffness
• Anomalous Expansion of the Copper-Apical Oxygen Distance in Superconducting La${}_2$CuO${}_4$ - La${}_{1.55}$Sr${}_{0.45}$CuO${}_4$ Bilayers
• Coherence, incoherence and scaling along the c axis of YBa_2Cu_3O_{6+x}
• Enhancement of the superconducting transition temperature in cuprate heterostructures

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