Coulomb interaction engineering at YBa 2Cu3O 7-δ-SrTiO3 interface
La Mattina, F., Erni, R., Rossell, M. D., Bona, G. L., & Shengelaya, A.
Journal of Superconductivity and Novel Magnetism, 35(7), 1801-1805. (2022).
It has been proposed by Müller and Shengelaya that underdoped ultrathin layers of copper-oxide high-temperature superconductors (HTSs) sandwiched between high-dielectric-constant insulator layers could manifest increased superconducting critical temperature Tc. To check this hypothesis, we investigated structural and transport properties of YBa2Cu3O7-δ (YBCO) thin films sandwiched between SrTiO3 (STO) layers. Scanning transmission electron microscopy (STEM) showed that a high-quality interface is formed between YBCO and the top STO layers. An increase of Tc up to ΔT≈ 20 K was observed at these interfaces in case of underdoped YBCO films.