Quantum computers promise transformative capabilities in areas such as advanced materials design, drug discovery, optimisation, and secure communications. While many platforms have demonstrated the minimum requirements for a quantum computer, scaling up these devices remains an outstanding challenge. This theoretical physics project aims to develop new control techniques for quantum computers where information is stored in the internal state of trapped atomic ions, which are currently the highest performing quantum computing platform.

The key challenge in scaling up a quantum computer is maintaining high-accuracy logical operations (called quantum 'gates'), while keeping the speed of this logical operations faster than the timescale at which quantum information is lost due to environmental interactions. In trapped-ion quantum computers, there are two main bottlenecks to scaling up to hundreds or thousands of physical quantum bits ('qubits'). First, conventional gate mechanisms slow down considerably and perform worse in the presence of a large number of atomic qubits. Second, existing architectures are limited by the need to physically move ions between spatially separated trapping zones, which requires additional cooling stages to combat transport-induced heating of the atomic ions.

This theoretical physics project aims to address bottlenecks in current trapped-ion quantum computers, by using computer optimisation to design optimal pulses or pulse sequences to improve the performance of logical operations. This project will extend our previous work studying long chains of atomic qubits [1] to study general geometries, parallelisation, and control of the trapping fields.

[1] Savill-Brown et al. PRL 136 (19), 190802 (2026)

No background is required for this project apart from undergraduate quantum mechanics.