Application of High-Fidelity, High-Speed Remote Entanglement of Trapped Ion Qubits to Fundamental Quantum Information Processing

Trapped ions have many useful properties that make them a suitable candidate for the implementation of quantum algorithms, such as long coherence times and the ability to entangle them in a highly controllable way through the mutual Coulomb repulsion of the ions that mediates a coupling between them. However, the number of qubits must be significantly increased to render quantum information processing competitive with classical computers. The two most advanced proposals to scale trapped-ion quantum processors to larger numbers of qubits rely either on physically shuttling individual ions between different processor modules or photonic probabilistic links.
In this regard, as a doctoral student, I aim to contribute to the progress at the scientific forefront of quantum information research and take part in the challenge to build a scaled-up ion trap quantum computer for the first time, adhering to the proposal involving photonic probabilistic links.
Improvements on entanglement schemes between remote trapped ions are to be carried out. The fidelity of entanglement will be enhanced by a multi-detector scheme and using fibre networks. Employing the entanglement purification technique will allow to distil even higher fidelity entangled states that can be used to demonstrate controlled quantum dynamics over macroscopic distances, for example the two-qubit CNOT gate. The experiment might also enable state teleportation, remote state preparation and an implementation of the dense coding quantum information protocol. The entanglement generation rate will be improved by the installation of cavities that enhance the emission into the fibre mode, thereby increasing the photon collection efficiency.

This research falls under the Quantum Technologies ESPRC Research Theme.