Robust high-fidelity entangling gates using long-wavelength radiation for quantum computation

Lead Research Organisation: University College London
Department Name: London Centre for Nanotechnology

Abstract

Quantum computing is a developing field that promises to solve problems which are too hard for a classical computer. However, solutions for these problems can only be found if a fault-tolerant quantum computer is used. The resources needed for such a device are a large number of qubits that can reliably store information and high-fidelity quantum gates to execute the computation.

Furthermore, to be able to reliably perform operations, error correction protocols should be implemented. It was proven that this can be achieved in the presence of limited noise, which imposes a constraint on the lower limit for the gate fidelities, the error thresholds range between 10-4 and 10-2, depending on the noise model used. Error correction protocols use multiple physical qubits to encode a logical qubit, which will be used as the unit employed in computation. Consequently, there is a trade-off between the number of physical qubits necessary for computation and the gate fidelity: the higher the fidelity, the smaller the number of additional qubits needed to compensate for the gate-errors. Considering and overcoming these challenges will enable the implementation of quantum algorithms.

The proposed project will research techniques that can be used to implement entangling gates and increase their fidelity, speed and overall robustness. This will require to reduce the effect of noise sources on the gate functionality, which can lead to designing modifications to the hardware setup. Once these improvements have been made, the project will focus on demonstrating quantum algorithms. A parallel project that will be completed alongside the experimental work is the automation of the conducted experiments. This will enable the hardware used to be remotely accessible and it is a stepping stone towards making the system available to be used in solving different problems.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/S021582/1 30/09/2019 30/03/2028
2407122 Studentship EP/S021582/1 23/08/2020 29/09/2024 Madalina Mironiuc