Reentrant Zero Resistance at Finite Magnetic Fields in Nanostructured Copper-Oxide Superconductor Films
Sprache des Vortragstitels:
Englisch
Original Tagungtitel:
73rd Annual Meeting of the Austrian Physical Society
Sprache des Tagungstitel:
Englisch
Original Kurzfassung:
Zero resistance is one of the most known properties of superconductors. In type-II superconductors, such as copper-oxide superconductors, the absence of moving magnetic flux
quanta is a prerequisite for a non-resistive state. Therefore, reentrant zero-resistance at a finite magnetic field is a strong indication of effective pinning of magnetic flux quanta.
As pinning centers, we introduce columns of point defects with suppressed critical temperature. We produce regular patterns of these defect columns by precisely positioning the focused beam of a helium ion microscope (He-FIB) on the surface of 30 to 50 nm thick superconductor films. The helium ions initiate collision cascades, displacing mainly oxygen atoms in the superconducting material while not affecting its crystal structure at an ion energy of 30 keV and moderate ion fluences.
Here, we present results of electronic transport measurements performed on nanostructured superconducting films: pronounced commensurability effects at magnetic fields as high as 6 T [1] and an ordered Bose glass behavior resulting from the interplay between pinning centers of different dimensionality [2, 3]. The strong pinning force of the artificial defects leads to reentrant zero resistance at a field of 3.8 T, and thanks to the precise arrangement of These defect columns, we can calculate the pinning force acting on a single flux quantum and ist temperature dependence.
Forschungs-