4 papers
Field Tuned Superconductor to Insulator Transitions in an Amorphous Film with an Imposed Multiply Connected Geometry
M. D. Stewart, Aijun Yin, J. M. Xu +1
We have observed multiple magnetic field driven superconductor to insulator transitions (SIT) in amorphous Bi films perforated with a nano-honeycomb (NHC) array of holes. The perio…
"Super weakly" coupled superconductivity in ultrathin superconductor-normal-metal bilayers
Zhenyi Long, M. D. Stewart, James M. Valles
Tunneling measurements of the temperature dependence of the electronic density of states (DOS) of ultrathin bilayers of Pb and Ag reveal that their superconducting energy gap, $Δ(T…
Ordered Nano-Crystal Arrays Spontaneously Form in Films Evaporated onto Nanopore Array Substrates
Niravun Pavenayotin, M. D. Stewart, James M. Valles +2
We present SEM images of films thermally evaporated onto Anodic Aluminum Oxide substrates that are patterned with a hexagonal array of 34 and 80 nm diameter holes spaced by 100 nm.…
Magnetic Flux Periodic Response of Nano-perforated Ultrathin Superconducting Films
M. D. Stewart, Zhenyi Long, James M. Valles +2
We have patterned a hexagonal array of nano-scale holes into a series of ultrathin, superconducting Bi/Sb films with transition temperatures 2.65 K 5 K. These regular p…