Speaker
Description
Superconducting nanostructures are attractive building blocks for future quantum and nanoelectronic technologies because they combine dissipationless transport, macroscopic quantum coherence, and strong sensitivity to geometry and dimensionality. In particular, extending superconductivity from planar systems to three-dimensional (3D) nanoscale architectures creates new opportunities to tailor electronic, magnetic, and optical functionalities through structural design.
Here we present a direct-write additive nanofabrication approach based on focused ion beam induced deposition for the realization of complex 3D superconducting nanostructures with nanoscale precision. This method enables the controlled growth of free-form geometries, including nanohelices, whose properties can be tuned through their shape, dimensions, and orientation. The fabricated nanohelices exhibit superconductivity with critical temperatures around 7 K and remain robust under high magnetic fields, up to 15 T depending on the field orientation relative to the helical axis, while displaying non-trivial transport behaviour linked to their 3D geometry.
Beyond single nanostructures, we show that geometry engineering provides access to additional functionalities. Chiral 3D superconducting nanoarchitectures display enhanced light–matter interaction, with strong circular dichroism and large dissymmetry factors compared with planar counterparts. In parallel, densely packed planar superconducting nanostructures exhibit enhanced vortex pinning, evidenced by resistance minima at well-defined magnetic fields associated with commensurability effects between the vortex lattice and the artificial geometry. We also demonstrate that the superconducting response of nanowires can be modulated by external electric fields, highlighting the possibility of actively tunable superconducting nanoelements.
Overall, these results establish focused ion beam direct-write nanofabrication as a versatile platform for designing advanced nanosuperconductors in which superconductivity, 3D geometry, chirality, and field tunability can be combined within a single nanoscale system.