Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

academic collection --- 538.945 <043> --- 538.945 <043> Superconductivity--Dissertaties --- Superconductivity--Dissertaties --- Theses

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

More than 110 years since its discovery, superconductivity is still a very dynamic research area that keeps puzzling and driving the scientific community. Below a certain critical temperature, a superconductor exhibits zero electrical resistance and doesn’t allow an applied magnetic field to penetrate inside it. Moreover, this intriguing phenomenon cannot be described by classical physics alone: it has a quantum mechanical nature displayed on a macroscopic scale. As such superconducting nanodevices show great potential for applications related to quantum technology, e.g. sensors, and qubits. The majority of these devices are based on the Josephson effect. When two superconducting electrodes are weakly coupled, they form a very unique electrical component. Between these two superconducting electrodes, a so-called `supercurrent' can flow. How this supercurrent moves from the first superconductor to the second, depends on the properties of the weak link in between them. A fingerprint of this behavior is the current-phase relation (CPR): its shape reflects how the supercurrent is modified during the `crossing' of the coupling element. For example: the CPR of a junction with an insulating weak link is sinusoidal, while that of a junction with a long geometric constriction as a weak link is linear. These weak links, known as nanobridges, exhibit some interesting properties. As mentioned before, their CPR is linear and can be described using a quantity known as the kinetic inductance. The kinetic inductance indicates the coupling strength between the two superconducting electrodes and is of importance for their applications as memory devices and. Although nanobridges show a plethora of interesting functionalities, a detailed characterization as a function of its dimensionality is still missing. In this work, the nanobridge as a weak link is investigated by embedding two nanobridge type weak links in a circular loop, resulting in a Superconducting Quantum Interference Device (SQUID). The properties of the nanobridge can be determined by measuring the device characteristics of these nanobridge-based SQUIDS using electrical low-temperature (close to absolute zero) and low-noise transport measurements. The aim of this thesis to determine the kinetic inductance of the embedded nanobridge as a function of the nanobridge dimensions. Furthermore, investigating and controlling the different SQUID energy states present. Therefore determining their stability and observing the transitions between these energy states to learn more about the dynamics present. The results of this experimental investigation can be summarized as follows. The coupling strength between the superconducting banks, the kinetic inductance, can be determined by measuring the response of a nanobridge-based SQUID. The lithographic control over the kinetic inductance of the nanobridge is demonstrated, which scales with the nanobridge aspect ratio (Length/Width). This allows the tuning of the SQUID's response and sensitivity. The SQUID can be prepared in a specific energy state which remained stable for several hours. This allowed identifying the transitions between the different energy states. The easy determination and lithographic control of the kinetic inductance described in this work are of relevance and will prove useful for the implementation of future devices.

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

By covering theory, design, and fabrication of nanostructured superconducting materials, this monograph is an invaluable resource for research and development. Examples are energy saving solutions, healthcare, and communication technologies. Key ingredients are nanopatterned materials which help to improve the superconducting critical parameters and performance of superconducting devices, and lead to novel functionalities. ContentsTutorial on nanostructured superconductorsImaging vortices in superconductors: from the atomic scale to macroscopic distancesProbing vortex dynamics on a single vortex level by scanning ac-susceptibility microscopySTM studies of vortex cores in strongly confined nanoscale superconductorsType-1.5 superconductivityDirect visualization of vortex patterns in superconductors with competing vortex-vortex interactionsVortex dynamics in nanofabricated chemical solution deposition high-temperature superconducting filmsArtificial pinning sites and their applicationsVortices at microwave frequenciesPhysics and operation of superconducting single-photon devicesJosephson and charging effect in mesoscopic superconducting devicesNanoSQUIDs: Basics & recent advancesBi2Sr2CaCu2O8 intrinsic Josephson junction stacks as emitters of terahertz radiation|Interference phenomena in superconductor-ferromagnet hybridsSpin-orbit interactions, spin currents, and magnetization dynamics in superconductor/ferromagnet hybridsSuperconductor/ferromagnet hybrids

Condensed matter physics (liquid state & solid state physics) --- Quantum physics (quantum mechanics & quantum field theory) --- Materials science --- Superconducters --- nanostructure