Superconducting flux transformers for the modulation of flux-tunable resonators
Ladda ner
Typ
Examensarbete för masterexamen
Master's Thesis
Master's Thesis
Program
Nanotechnology (MPNAT), MSc
Publicerad
2024
Författare
Dakroury, Karim
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Pushing the limits of quantum mechanics to larger objects is a goal of current research efforts. One approach to test the limits of quantum mechanics is to achieve quantum superposition with a macroscopic object on the order of micrometers. A possible experimental approach in this direction is given by coupling a magnetically levitated particle to a superconducting flux-tunable resonator. This system can allow us to sense the particle’s motion and the flux-tunable resonator will act as the quantum sensor and the readout for the particle. This system exploits flux coupling between the particle and the flux-tunable resonator. An approach of realizing this flux coupling is by implementing a flux transformer which is the main goal of this thesis. In this thesis we demonstrate a theoretical model to optimize the geometry of the flux transformer for maximum flux transfer efficiency. The theoretical analysis is verified with simulations on COMSOL Multiphysics. Then, a reliable fabrication recipe has been developed which had high yield of superconducting flux transformer and flip-chip devices. A novel flip-chip assembly technique was implemented with usage of Indium microspheres as superconducting interconnects. The thin-film of the materials used for the flux transformer and the flip-chip devices were characterized to demonstrate their superconductivity. Finally, a proof-of-principle for flip-chip based modulation of a flux-tunable resonator is demonstrated.
Beskrivning
Ämne/nyckelord
flip-chip , superconductivity , nanofabrication , flux transfomer , underbump metallization