Title: Shiba Bound States across the mobility edge in doped InAs nanowires,
Abstract: We present a study of Andreev Quantum Dots (QDots) fabricated with
small-diameter (30 nm) Si-doped InAs nanowires where the Fermi level can be
tuned across a mobility edge separating localized states from delocalized
states. The transition to the insulating phase is identified by a drop in the
amplitude and width of the excited levels and is found to have remarkable
consequences on the spectrum of superconducting SubGap Resonances (SGRs). While
at deeply localized levels, only quasiparticles co-tunneling is observed, for
slightly delocalized levels, Shiba bound states form and a parity changing
quantum phase transition is identified by a crossing of the bound states at
zero energy. Finally, in the metallic regime, single Andreev resonances are
observed.