A Josephson junction is a device where a thin insulating barrier or a nanostructure is placed between two superconducting leads. Such a junction is essential to superconducting qubits that store... Show moreA Josephson junction is a device where a thin insulating barrier or a nanostructure is placed between two superconducting leads. Such a junction is essential to superconducting qubits that store quantum information due to its anharmonic spectrum. Therefore, understanding the physics of these junctions is crucial for predictions of the qubit's main qualities, such as the dephasing and relaxation time. Most modern superconducting qubits use Josephson junctions with an insulating barrier (tunneling junction). One of this thesis aims is to explore other possibilities that may allow for better properties of the qubit. Show less
Topological superconductivity is a novel phenomenon, that has recently been predicted to exist in quantum wires. The first signatures of this new superconducting state have recently been reported.... Show moreTopological superconductivity is a novel phenomenon, that has recently been predicted to exist in quantum wires. The first signatures of this new superconducting state have recently been reported. The difference with usual superconductors is the appearance of conducting edge states. It is of interest to investigate how all the well-known effects of superconductivity, including Andreev reflection and Josephson effect, are modified by these edge states, and also to discover new effects that appear only in topological superconductors. This investigation is the main topic of the thesis. Show less