  This work presents a computational analysis of a superconducting transmon
qubit design, in which the superconductor-insulator-superconductor (SIS)
Josephson junction is replaced by a co-planar,
superconductor-constriction-superconductor (ScS) nanobridge junction. Within
the scope of Ginzburg-Landau theory, we find that the nanobridge ScS transmon
has an improved charge dispersion compared to the SIS transmon, with a tradeoff
of smaller anharmonicity. These calculations provide a framework for estimating
the superconductor material properties and junction dimensions compatible with
gigahertz frequency ScS transmon operation.
