Thulium Doped Garnets for Quantum Repeaters and Optical Quantum Memory

Quantum memories will prove to be an invaluable tool for distributing entangled quantum states over distance. Many novel materials for this purpose are being investigated and key among them are rare earth ion doped crystals. These materials possess a great number of potential combinations of host crystal and ion species for further study, some...

Theoretical advances in practical quantum cryptography

Most of themainstream cryptographic protocols that are used today rely on the assumption that the adversary has limited computational power, and that a given set of mathematical problems is hard to solve (on average), i.e. that there is no polynomial time algorithm that solves these problems. While these assumptions are reasonable for now they...

Building blocks of quantum repeater networks

Diamond-based quantum networks with multi-qubit nodes

Quantum networks promise to be the future architecture for secure communication and distributed quantum computation. This thesis describes experiments on nitrogenvacancy (NV) centres that lead towards a versatile multi-node quantum network consisting ofmulti-qubit nodes.<br/>The NV centre in diamond is a spinful optically-active crystal defect....