Quantum gravity simulation on a quantum computer

A unified theory encompassing general relativity and quantum mechanics has remained elusive since research began in the 1930s. Current approaches addressing this challenge have progressed slowly and have made limited predictions for this theory.

However, the recent application of tensor networks to the Anti-de Sitter/Conformal field theory (AdS/CFT) duality offers a fresh and promising route to gain insights into quantum gravity. This duality conjectures that quantum gravity theories defined in asymptotically anti-de Sitter spaces of d + 1 dimensions are dual to conformal field theories defined on their d-dimensional boundaries. By leveraging tensor networks, the entanglement structure and the emergence of spacetime geometry can be effectively captured. The mathematical tractability of discrete tensor networks also circumvents the complexities inherent in other approaches to quantum gravity. A discrete spacetime realisation of the AdS/CFT correspondence would useful for the development of quantum error correcting codes and for providing a numerical framework to study strong interactions.

The objective of this PhD research is to investigate whether conformal dual-unitary circuits constitute a discrete spacetime realisation of the AdS/CFT correspondence and serve as a viable toy model of quantum gravity. This investigation will involve characterising the underlying physics of this model and developing methods for its efficient simulation on a quantum computer.

The first and most important impact of our Centre will be through the cross-disciplinary technical training it provides for its students. Through this training, they will have not only skills to control and exploit quantum physics in new ways, but also the background in device engineering and information science to bring these ideas to implementation and to seek out new applications. Our commercial and governmental partners tell us how important these skills are in the growing number of people they are hiring in the field of quantum technologies. In the longer term we expect our graduates to be prominent in the development of new technologies and their application to communication, information processing, and measurement science in leading university and government laboratories as well as in commercial research and development. In the shorter term we expect them to be carrying out doctoral research of the highest international quality.

Second, impact will also flow from the students' approach to enterprise and technology transfer. From the outset they will be encouraged to think about the value of intellectual property, the opportunity it provides, and the fundraising needed to support research and development. As students with this mindset come to play a prominent part in university and commercial laboratories, their common background will help to break down the traditional barriers between these sectors and deliver the promise of quantum technologies for the benefit of the UK and world economies. Concrete actions to accelerate this impact will include entrepreneurship training and an annual CDT industry day.

Third, through the participation it nucleates in the training programme and in students' research, the Centre will bring together a community of partners from industry and government laboratories. In the short term this will facilitate new collaborations and networks involving the partners and the students; in the long term it will help to ensure that the supply of highly skilled people from the CDT reaches the parts of industry that need them most.

Finally, the CDT will have a strong impact on the quantum technologies training landscape in the UK. The Centre will organise training events and workshops open to all doctoral researchers to attend. We will also collaborate with CDTs in the quantum technologies and related research areas to coordinate our efforts and maximise our joint impact. Working in consort, these CDTs will form a vibrant national training network benefitting the entire UK doctoral research community.