New method for the controlled creation of sub-15 nm aluminum nanowires to probe the 1D superconductor-insulator transition

We have developed a new method for the creation of sub-15 nm aluminum nanostructures using a sodium bicarbonate solution. Using PMMA masks patterned with e-beam lithography, we can controllably etch lithographically-produced nanostructures while measuring their resistances in-situ using a 4-probe measurement. This technique allows for precise control over the final resistance and thus can be used to create a wide variety of nanodevices. In particular, this technique allows for the creation of nanowires to probe the superconductor-insulator transition in 1D.