Improving 1 and 2-Qubit Gate Fidelities for Laser-Written Nitrogen Vacancy Centres in Diamond Membranes

Project Description

If a quantum computer could be built with enough qubits, it would be able to solve problems that are intractable with the classical computers we have now. A leading design for this is to build nodes with five or more interacting qubits, and then link up many of these nodes. Nitrogen vacancy centres (NVC) in diamond at cryogenic temperatures have been used to demonstrate this linking by entangling their electron spins optically. The nuclear spins coupled to NVC can have long coherence times of over 10 seconds.

This project will make use of our laserwritten NVC and the laser-written electrical wires we can create around them [1, 2]. The laser writing is done by the group of our collaborator Patrick Salter in Oxford University. We will build arrays of these qubits inside diamond membranes, and use composite pulses to demonstrate high-fidelity control of both the electron spin and the coupled 13C nuclear spins. Initial experiments will be at room temperature, but cryogenic measurements will be used also as this is needed to entangle two NVC.

We have also built related experiments including versions that operate with a large ensemble of NVC, which we want to commercialise as a magnetometer. We collaborate with Jason Smith’s group in Oxford because they are working on speeding up the optical entanglement of two NVC as part of the UK National Quantum Computation and Simulation (QCS) Hub. This PhD studentship is fully funded by the EPSRC through this Hub.

The start date for the project will be 1st October 2020.

Funding Information

The project provides full funding for stipend and fees for four years, and includes a generous research training support grant.

Eligibility Requirements

You should have obtained, or be about to obtain a First or Upper Second Class UK Honours degree in Physics, Engineering or a related subject. Applicants with equivalent qualifications gained outside the UK will also be considered.

Supplementary Information

The successful applicant will join a team of over 10 academics and 20 PhD students in the departments of Physics, Chemistry, Engineering and the Warwick Manufacturing Group all researching into different aspects of Diamond Science and Technology. Warwick has excellent facilities for characterisation and processing of diamond, as well as the fabrication of micro/nano diamond devices and an exceptionally strong record of successful collaboration with industry.

The Physics department is proud to be an IOP Juno Champion and a winner of an Athena Swan Silver Award, reflecting our commitment to equal opportunity and to fostering an environment on which all can excel.

References

[1] Y.-C. Chen et al., Nat Photon 11, 77 (2017). [2] C. J. Stephen et al., Physical Review Applied 12, 064005 (2019)

To apply for this PhD, please use the following application link: https://warwick.ac.uk/fac/sci/dst/phd_projects

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