Masters Defence: Thomas Antonio Marangoni

Title: Detection and tuning of non-local conductance in a nanowire Cooper pair splitter


This thesis presents non-local conductance measurements on a total of 16 resonance crossings in a nanowire Cooper pair splitter. The Cooper pair splitter has two gold electrodes acting as the normal contacts and an aluminium electrode acting as the superconducting contact, connected by an InAs nanowire. The majority of the non-local signals consisted of a positive and a negative peak, attributed to the transition of the ground state in the superconductor from a singlet to a doublet state and vice-versa. Afterwards, the bottom gates on the device were used to tune the Cooper pair splitter to several configurations, attempting to find the regime with the highest non-local efficiency. The splitter was successfully manipulated, detecting an increase in efficiency after several configurations. This thesis has successfully demonstrated the possibility of configuring a Cooper pair splitter device to a more optimal regime, a step towards creating a reproducible and highly efficient source of entangled electrons.