Text
High resolution STM spectroscopy is a powerful tool to study superconducting excitations at the atomic scale.
I will explore this on two systems.
The first is a molecular spin (FeTPP-Cl) deposited on a proximitized Au/V substrate. The interaction between the exchange coupling and anisotropy gives raise to multiple many-body excitations inside and outside the superconducting gap, which we describe with a single-site superconductor model.
The second consists of Pb islands on graphene, where Coulomb blockade and superconductivity coexist. We observe asymmetric quasiparticle and Josephson currents due to an excess charge present on the island. Applying tip bias pulses, we tune this charge acting as an effective gating. This allows the measurements of gate-dependence dI/dV maps without a gate electrode and the tuning of the transport asymmetry, realizing a switchable Cooper pair diode.