Optimal Implementation of Quantum Circuits on Noisy Hardware

"Noisy intermediate scale quantum (NISQ) devices have undergone rapid development in recent years, and as such a need has arisen for the development of highly e cient algorithms that can make proper use of them. One technique that has found ubiquity in quantum simulation is the Suzuki-Trotter decomposition, which approximates unitary evolution operators de ned by complex Hamiltonians via decomposition into a finite number of elementary quantum gates. The approximation is exact as the number of Trotter steps, n ! 1, with the number of gates increasing correspondingly.
In order to curtail circuit depth and thus reduce gate errors, simulations are limited to a finite n, thus resulting in a non-zero Trotter error; the role of ordering the resulting gates in minimising this error for a given nis (perhaps surprisingly) very signficant due to their non-commutativity, and yet optimal orderings are not well understood. In this project, reinforcement learning is utilised to nd optimal or close-to-optimal Trotter orders. Deep recurrent Q networks (DRQNs) are primarily used, following on from their successful utilisation in optimising gate sequences for quantum memory. Simulations are performed both classically and via computations on real superconducting quantum devices."

The main impact of the proposed Hub will be in training quantum engineers with a skillset to understand cutting-edge quantum research and a mindset toward developing this innovation, and the entrepreneurial skills to lead the market. This will grow the UK capacity in quantum technology. Through our programme, we nurture the best possible work force who can start new business in quantum technology. Our programme will provide multi-level skills training in quantum engineering in order to enhance the UK quantum technologies landscape at several stages. Through the training we will produce quantum engineers with training in innovation and entrepreneurship who will go into industry or quantum technology research positions with an understanding of innovation in quantum technology, and will bridge the gap between the quantum physicist and the classical engineer to accelerate quantum technology research and development. Our graduates will have to be entrepreneurial to start new business in quantum technology. By providing late-stage training for current researchers and engineers in industry, we will enhance the current landscape of the quantum technology industry. After the initial training composed of advanced course works, placements and short projects, our students will act as a catalyzer for collaboration among quantum technology researchers, which will accelerate the development of quantum technology in the UK. Our model actively encourages collaboration and partnerships between Imperial and national quantum tehcnology centres and we will continue to maintain the strong ties we have developed through the Centre for Doctoral Training in order to enhance our on-going training provisions. The Hub will also have an emphasis on industrial involvement. Through our new partnerships students will be exposed to a broad spectrum of non-academic research opportunities. An important impact of the Hub is in the research performed by the young researchers, PhD students and junior fellows. They will greatly enhance the research capacity in quantum technology. Imperial College has many leading engineers and quantum scientists. One of the important outcomes we expect through this Hub programme is for these academics to work together to translate the revolutionary ideas in quantum science to engineering and the market place. We also aim to influence industry and policy makers through our outreach programme in order to improve their awareness of this disruptive technology.