Variational Quantum Linear Solver for Finite Element Problems: a Poisson equation test case

This research investigates the possibility of solving one dimensional Poisson's equation on quantum computers using the Variational Quantum Linear Solver (VQLS) as a simplified test case for fluid dynamics applications. In this work, Poisson's equation is discretized with the finite element method and the resulting matrix is decomposed as a...

Bell inequalities and their maximal violation

Bell inequalities are certain probabilistic inequalities that should hold in the context of quantum measurement under assumption of a local hidden variable model. These inequalities can be violated according to the theory of quantum mechanics and have also been violated experimentally. Bell inequalities were therefore historically used to...

Quantum measurement and real-time feedback with a spin-register in diamond

Gaining precise control over quantum systems is crucial for applications in quantum information processing and quantum sensing and to perform experimental tests of quantum mechanics. The experiments presented in this thesis implement quantum measurements and real-time feedback protocols that can help to achieve these goals using single electron...

Feedback control of superconducting quantum circuits

Superconducting circuits have recently risen to the forefront of the solid-state prototypes for quantum computing. Reaching the stage of robust quantum computing requires closing the loop between measurement and control of quantum bits (qubits). This thesis presents the realization of feedback control of superconducting qubits based on...

Quantum measurement and entanglement of spin quantum bits in diamond

This thesis presents a set of experiments that explore the possible realisation of a macroscopic quantum network based on solid-state quantum bits. Such a quantum network would allow for studying quantum mechanics on large scales (meters, or even kilometers), and can open new possibilities for applications in quantum information processing. A...

On the Quantum Measurement of Superconducting Flux Qubits