Quantum Dots Coupled to Superconductors

The search for Majoranas bound states has witnessed heated efforts in the past decade. This field of research lies at the intersection of both scientific and commercial interests. The Majorana quasiparticle, being its own antiparticle and exhibiting non-abelian exchange statistics, is a unique member of the family of condensed-matter...

Induced superconductivity in antimony-based two-dimensional electron gases

Majorana zero modes (MZMs) are a topic of intense research as they constitute the main building block of topological qubits - a qubit type with potentially enhanced coherence time. A promising way to create these quantum states is to couple a one-dimensional (1D) semiconducting segment with spin-orbit interaction to a superconductor, in the...

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...

Gate-based readout of hybrid quantum dot systems

Quantum mechanics yields exciting opportunities for developing novel technologies. In particular, quantum computation enables performing otherwise intractable calculations. However, unwanted disturbances to the quantum bits (qubits) form a formidable challenge for its implementation. Topologically encoding information protects against these...

Hybrid Josephson junction-based quantum devices in magnetic field

The technology of quantum computing is believed to solve certain computational problems significantly faster than classical computers, enabling classically inaccessible problems. However, the technology is still in its infancy and it is still too early to conclude which physical system(s) will form the basis of tomorrow's quantum computer. Small...

Advances in semiconducting-superconducting nanowire devices

After a century from the quantum description of nature, the scientific community has laid the basis for using nature's properties to our advantage. The quantum technology vision stems from the idea of capitalizing these principles in various sectors, such as computation and communication. However, in contrast to classical processors, encoding...

Spins in Josephson Junctions

Quantum technology is an exciting research area that has gained a lot of interest in the past few decades with the advances made in quantum computing. The quantum computer promises speedups that are impossible to achieve with classical computers. It does so by exploiting quantum mechanical properties such as entanglement and superposition with...

Zero-energy states in Majorana nanowire devices

In the voyage towards solving increasingly challenging computations of physical systems, quantum computation has arisen as a contender for conventional computational approaches. To address the issue of keeping the required quantum mechanical states sufficiently stable against environmental disturbances, novel proposals suggested to employ...

Microkelvin Nanoelectronics

Of all parameters, determining the behaviour of a physical system in the laboratory, temperature is one of the most important, if not themost important. The study of solid matter at cryogenic temperatures revealed unexpected phenomena like superconductivity and was closely related to the verification of new and revolutionary concepts in...

Superconducting islands and gate-based readout in semiconductor nanowires

Quantum computers can solve some problems exponentially faster than classical computers. Unfortunately, the computational power of quantum computers is currently limited by the number of working qubits. It is difficult to scale up these systems, because qubits are easily affected by noise in their environment. This noise leads to decoherence:...

Magnetic field compatible hybrid circuit quantum electrodynamics

Majorana bound states (MBSs) are novel particles predicted to be created when superconductor/semiconductor hybrid structures with strong spin-orbit coupling are subjected to strong magnetic fields. Expected to exhibit non-Abelian exchange statistics, they could form the basis of a new kind of quantum computer that is inherently protected from...

Quantum transport in nanowire networks

Quantum technology is a promising area of research, with the quantum computer as the prime example. Quantum computers can perform calculations thought to be impossible by conventional means. The fundamental building block of a quantum computer is a qubit, which is a quantumsystem which can be used to process and store quantuminformation. Most...

Superconducting quantum interference in semiconducting Josephson junctions

A topological superconductor is a new state of matter that attract a lot of interest for its potential application in quantum computers. However, there is no single material known to host this state of matter. In this thesis, combinations of superconductors and semiconductors are investigated experimentally with the goal to engineer such a...

Spin-orbit interaction in ballistic nanowire devices

Similar to their charge, electrons also posses an intrinsic magnetic moment called spin. Whenmoving through an electric field, electrons experience and effective magnetic field in their restframe which will interact with the spin and influence its direction. This spinorbit interaction creates a measurable shift in the splitting of atomic energy...

Superconducting InSb nanowire devices

Josephson junctions form a two-level system which is used as a building block for many types of superconducting qubits. Junctions fabricated from semiconducting nanowires are gate-tunable and offer electrostatically adjustable Josephson energy, highly desirable in qubit architecture. Studying nanowire weak links is therefore important for future...

Semiconductor Nanowire Josephson Junctions: In the search for the Majorana

Due to the collective behavior of electrons, exotic states can appear in condensed matter systems. In this PhD thesis, we investigate semiconducting nanowire Josephson junctions that potentially have Majorana zero modes (MZM) as exotic states. MZM are expected to form a robust quantum bit and quantum operations are done by interchange, otherwise...