Fig. 4: Coaxial geometries.
From: Surface loss calculations and design of a superconducting transmon qubit with tapered wiring
Drawings of coaxial geometries considered here. a Cross section of coax, with inner radius r and outer radius R. b Cross section of flat coax, with width \(2\overline{r}\) of inner thin film. The surface energies of the metal and substrate are Um and Us respectively, with the subscripts referring to the coax (Uc) or flat coax (Uf) cases. The x-direction is horizontal and the shaded regions correspond to the substrate.
