Transverse vortex commensurability effect and sign change of the Hall voltage in superconducting YBa2Cu3O7−δ thin films with a nanoscale periodic pinning landscape

Authors: G. Zechner and W. Lang

Physical Review B 98, 104508 (2018)

Abstract:

The transverse (Hall) voltage in thin films of the high-temperature superconductor YBa2Cu3O7−δ with an artificial periodic pinning array is investigated. Columnar defect regions along the crystallographic c axis, in which superconductivity is suppressed, are created by irradiation with He+ ions through a silicon stencil mask. The commensurate arrangement of magnetic flux quanta with the artificial defect lattice is confirmed by maxima of the critical current and minima of the resistance, respectively. The magnetic field dependence of the transverse voltage reveals a commensurability effect characterized by a narrow peak of the Hall coefficient with reversed polarity compared to the background signal. This signature of vortex matching disappears at larger vortex velocities substantiating its close connection with enhanced pinning of vortices at the periodic pinning landscape.