Oxygen-isotope effect on the superconducting gap in the cuprate superconductor Y_{1-x}Pr_xBa_2Cu_3O_{7-δ}

Abstract

The oxygen-isotope (^{16}O/^{18}O) effect (OIE) on the zero-temperature superconducting energy gap Δ_0 was studied for a series of Y_{1-x}Pr_xBa_2Cu_3O_{7-δ} samples (0.0\leq x\leq0.45). The OIE on Δ_0 was found to scale with the one on the superconducting transition temperature. These experimental results are in quantitative agreement with predictions from a polaronic model for cuprate high-temperature superconductors and rule out approaches based on purely electronic mechanisms.

5 pages, 3 figures