Quantum size effects in ultra-thin YBa₂Cu₃O_7 - x films.

ABSTRACT: The d-wave symmetry of the order parameter with zero energy gap in nodal directions stands in the way of using high-temperature superconductors for quantum applications. We investigate the symmetry of the order parameter in ultra-thin YBa₂Cu₃O_7 - x (YBCO) films by measuring the electrical transport properties of nanowires aligned at different angles relative to the main crystallographic axes. The anisotropy of the nanowire critical current in the nodal and antinodal directions reduces with the decrease in the film thickness. The Andreev reflection spectroscopy of the nanoconstrictions shows the presence of a thickness-dependent energy gap that does not exist in bulk YBCO. We find that the thickness-dependent energy gap appears due to the quantum size effect

SUBMITTER: Lyatti M 

PROVIDER: S-EPMC11436648 | biostudies-literature | 2024 Sep

REPOSITORIES: biostudies-literature