Physicist at CNRS-Thales Lab, France
The field of fluxtronics is based on transmitting and processing information using quanta of magnetic flux in a type-II superconductor. In this study, temperature is used to reversibly tune the energy landscape of flux vortices pinned in a patterned sample of YBa2Cu3O7, providing an avenue to thermally switchable device functionalities.
We experimentally study superconducting YBa2Cu3O7 thin films with artificial vortex pinning arrays created via masked ion irradiation. In particular, we compare a series of arrays (2D periodic non-Bravais lattices) in which the density of pinning sites is nonuniform within the unit cell. The series consists of variants of a canonical array, which is gradually deformed by varying the separation between pinning centers within the unit cell.
Interestingly, the array deformation produces a very striking evolution of magnetoresistance flux-matching effects, which strongly depend on temperature. The key to this unusual behavior is the nanoscale spatial modulation of the superconducting critical temperature produced via masked ion irradiation.