Title: Conduction Channels of an InAs-Al nanowire Josephson weak link,
Abstract: We present a quantitative characterization of an electrically tunable
Josephson junction defined in an InAs nanowire proximitized by an
epitax-ially-grown superconducting Al shell. The gate-dependence of the number
of conduction channels and of the set of transmission coefficients are
extracted from the highly nonlinear current-voltage characteristics. Although
the transmissions evolve non-monotonically, the number of independent channels
can be tuned, and configurations with a single quasi-ballistic channel
achieved.