Spinful Andreev States in Superconducting Circuits

The growing understanding of the physics of superconductor-semiconductor nanostruc- tures is a key driver for the development of emerging quantum technologies. The elemen- tary excitations of these hybrid nanostructures are Andreev bound states. To further our knowledge about their intricate physics, new tools must be used to study them. This...

A study of two-dimensional superconductivity at oxide interfaces using waveguide resonators

Shadow-wall lithography as a novel approach to Majorana devices

The development of quantum computers is perhaps one of the most exciting innovations of our time. The most investigated quantum computers, however, suffer from the fact that quantum information is lost due to interaction between the quantum bits and their environment. As a radically different approach, it has been proposed that one can instead...

Quantum Properties in Hybrid Nanowire Devices

Quantum computing is a flourishing field of scientific and technological research. The development of quantum computing in the past decades is the so-called second quantum revolution, where various aspects of quantum physics, such as entanglement and superposition, are used to form the main building block of computation — the quantum bit, or...

Quantum effects of superconducting phase

The microscopic theory of superconductivity proposed by John Bardeen, Leon Cooper, and John Robert Schrieffer has been a vital milestone of condensed matter physics and the basis of development of new quantum technologies. It explained the superconductivity as an emergent phenomenon arising from weak phonon-mediated attraction of individual...

Applied and fundamental studies of vibrating 2D membranes

This thesis encompasses both applied and fundamental studies of suspended van der Waals materials. Chapters 1 and 2 give an introduction to the field of 2D materials and some of the critical methods which facilitate the study of the suspended structures. In Chapters 3 and 4 we focus on the applications of graphene in barometric pressure sensors...

Quantum transport at oxide interfaces

The realization of interfaces between different transition metal oxides has heralded a new era of materials and physics research. Notably, it enabled a uniquely diverse set of coexisting physical properties to be combined with an ever-increasing degree of experimental control. The primary focus of this thesis is the celebrated interface between...

Quantum Transport Phenomena in Magnetic Molecules

In this work, we investigate a series of physical phenomena resulting from the confinement of electrons in those localised charge and spin quantum boxes generically called molecules.

Quantum transport in superconducting hybrids: Molecular devices and layered materials

In this thesis we investigate superconducting hybrids made from two material systems, namely, molecules and layered materials. For studies of superconducting phenomena in molecular junctions we develop two platforms which rely on the superconducting proximity effect to preserve pre-existing nano-gap formation techniques and bonding chemistries....

Electrodynamics of strongly disordered superconductors

Thin films of superconducting materials with a high resistance in the normal state, such as TiN, NbTiN, NbN and InO, are intensively studied from both an application and a fundamental point of view. A spatially inhomogeneous superconducting state can arise in these materials as a result of the strong disorder. This Thesis provides an...

Quasiparticle dynamics in aluminium superconducting microwave resonators

This thesis describes the intrinsic limits of superconducting microresonator detectors. In a superconductor at low temperature, most of the electrons are paired into so called Cooper pairs, which cause the well-known electrical conduction without resistance. Superconducting microwave resonators have therefore very high quality factors and are...

Non-equilibrium electron transport in mesoscale superconducting hybrids

This thesis focusses on driven superconducting heterostructures. Both experimentally and theoretically we address the following questions: (a) how does the presence of different metallic and dielectric materials influence the electronic properties of a driven superconductor? (b) how does a non-equilibrium electron distribution arise and how does...

Photon-detecting superconducting resonators

One of the greatest challenges in astronomy is observing star and planetary formation, redshifted distant galaxies and molecular spectral ‘fingerprints’ in the far-infrared spectrum of light, using highly sensitive and large cameras. In this thesis we investigate superconducting resonators for photon detection. In superconductors the electrons...

Singlet and triplet supercurrents in disordered mesoscopic systems

This thesis describes a series of experiments and a theoretical study in order to understand and control the behavior of electrons in many-body systems. In particular, the experiments concentrate on competition between the - antagonistic - electronic states of superconductivity and ferromagnetism, and are strongly motivated by the recent...

Magnetic Properties of Uranium Based Ferromagnetic Superconductors

Ferromagnetism and superconductivity have long been thought to be mutually exclusive. Recently however it was found that the compounds UGe2, URhGe and UIr belong to a class of materials in which ferromagnetisme and superconductivity appear simultaneously. One characteristic property of these compounds is the existence of strong correlations...

Quantum transport in molecular devices and graphene

As a result of progress in nanotechnology, smaller and smaller electronic circuits can be made. The stage of electrically contacting even a single molecule has now been reached. This stimulates both fundamental and applied research alike. Molecular electronics is hence a booming new field that draws a lot of attention. In this research project...

Quantum transport in semiconductor nanowires

This thesis describes a series of experiments aimed at understanding the low-temperature electrical transport properties of semiconductor nanowires. The semiconductor nanowires (1-100 nm in diameter) are grown from nanoscale gold particles via a chemical process called vapor-liquid-solid (VLS) growth. The huge versatility of this material system...

Coherent Transport in Superconducting and Ferromagnetic Hybrid Systems