Novel architectures for neutral atom quantum computing

Research context and potential impact:

Neutral atoms in tweezer arrays have rapidly become a competitive platform for quantum computing, with demonstrated two-qubit gate fidelities over 99.5%, in systems that now regularly operate with several hundred qubits. At the same time, these systems offer very interesting new features for implementation of quantum operations (in both digital and analogue settings), with the ability to move atoms and change the effective coupling graph between qubits (even just using massively parallel nearest-neighbour operations in real space).

Recent demonstrations of multi-species experiments offer new opportunities for patterned readout, and also for the generation of patterned couplings that vary between chosen nodes of these graphs. Recently, we have explored how shuffling of atoms can give rise to fast scrambling, building particle entangled states in a time that scales as log(N). This project will look to extend these systems, with a substantial potential impact on new techniques for controlling and utilising these hardware platforms.

Aims and objectives: In this project, we will devise and analyse new ways to use the combination of moving atoms and multi-species experiments as a novel architecture for quantum computing, combined with open quantum systems, especially the possibility to put atoms in tweezers into optical cavities. There are a variety of international groups developing such experiments, which will enable new ways to generate interactions between distant atoms, as well as new readout techniques for use in quantum error correction.

In this context, we will study the underlying system properties, developing microscopic models and considering ways to control the system. We will then connect with potential applications, which are planned to include (1) digitally-controlled random walks on coupling graphs (2) quantum simulation of out-of-equilibrium problems with novel Hamiltonians that can be realised in these experiments.

In each case, we will determine the range of controllable models that can be realised, and identify connections to systems of interest in the modelling of modern quantum materials.

Novelty of the research methodology: We will be combining techniques from quantum optics to describe open quantum systems (such as stochastic Schrödinger equations and quantum state diffusion methods for atoms in optical cavities) with concepts from many-body systems out of equilibrium. The architectures we consider will be novel, and will open new pathways to realise quantum computing and simulation with neutral atoms.

Alignment to EPSRC's strategies and research areas: This studentship is directly aligned with the QCS Hub and connects to the QCI3 hub activities in quantum computing and simulation, and will contribute to the wider academic research in the National Quantum Technologies Programme This project falls within the EPSRC quantum technologies research area.