Nanowires with superconducting leads – Niels Bohr Institute - University of Copenhagen

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Nanowires with superconducting leads

In this master's thesis, a gated InAs nanowire was contacted by superconducting
aluminium leads. The effects observed in this device touch upon a large field of
mesocscopic transport topics. At low gate potentials, sequential tunneling and
cotunneling is observed, with gate dependent hybridization affecting inelastic
cotunneling. The BCS theory of superconductivity is introduced, and is used to
explain the behaviour of the device at bias potentials near the superconducting
gap. Especially first order Andreev reflections are seen to play a large role for
transport in this device. In some cases, these Andreev reflections are enhanced by
the Kondo effect.

Written for the Nano Electronics group.

Supervised by:
Jesper Nygård, Kasper Grove-Rasmussen, and Thomas Sand Jespersen.

Master's thesis defense by Anders Jellinggaard