Spin Qubits in Silicon and Germanium

Quantum computers based on semiconductor quantum dots are proving promising contenders for large scale quantum information processing. In particular, group IV based semiconductor hosts containing an abundance of nuclear spin-zero isotopes have made considerable headway into fulfilling the requirements of a universal quantum computer. Silicon (Si...

Performance benchmarking of silicon quantum processors

Benchmarking the performance of a quantum computer is of key importance in identifying and reducing the error sources, and therefore in achieving fault-tolerant quantum computation. In the last decade, qubits made of electron spins in silicon emerged as promising candidates for practical quantum computers. To understand their physical properties...

Quantum simulation with electron spins in quantum dots

More is more applies in particular to systems with interacting parts. These interactions enable the emergence of collective behaviour. Examples can be found among the behaviour of animals, such as the V-shaped formation of migrating geese and the flight of a flock of starlings. More examples are found among the electromagnetic properties of...

Hot qubits in silicon for quantum computation

The understanding of quantum mechanics enabled the development of technology such as transistors and has been the foundation of today’s information age. Actively using quantum mechanics to build quantum technology may cause a second revolution in handling information. However, to execute meaningful algorithms, largescale quantum computers have...

Circuit Quantum Electrodynamics with Single Electron Spins in Silicon

This dissertation describes a set of experiments with the goal of creating a super-conductor-semiconductor hybrid circuit quantum electrodynamics architecture with single electron spins. Single spins in silicon quantum dots have emerged as attractive qubits for quantum computation. However, how to scale up spin qubit systems remains an open...

Electrical manipulation and detection of single electron spins in quantum dots

Entanglement in Solid-State Nanostructures

The goal of this thesis is to investigate theoretically the generation and behaviour of multipartite entanglement for solid-state nanosystems, in particular electron spin quantum bits (so-called 'qubits') in quantum dots. A quantum dot is a tiny potential well where a single electron can be trapped. A quantum bit can be implemented in this...

Manipulation and Read-out of Spins in Quantum Dots

Besides an electric charge, electrons also have a tiny magnetic moment, called spin. In a magnetic field, the spin has two possible orientations: 'spin-up' (parallel to the field) and 'spin-down' (anti-parallel to the field) and can therefore be used as a quantum bit, the computational unit of a quantum computer. For quantum computations,...

Spin and charge in semiconductor nanowires

The research in this thesis is motivated by an interest in quantum physics and by the prospect of new applications based on the spin of electrons or holes. This work focuses on confining single spins in quantum dots, which can serve as building blocks of a future quantum computer. Such a computer exploits the unique features of quantum mechanics...

Coherence and control of a single electron spin in a quantum dot

An electron does not only have an electric charge, but also a small magnetic moment, called spin. In a magnetic field, the spin can point in the same direction as the field (spin-up) or in the opposite direction (spin-down). However, the laws of quantum mechanics also allow the spin to exist in both states at the same time (so-called...