Diamond Quantum Technologies: Advancements in Engineering NV Centre Devices

Defects in diamond crystals which form its colour centres are a very valuable source of quantum systems. The NV centres in diamond possess an electron spin state that can be used as an excellent spin qubit.

These qubits possess some unique features that make this an exciting system to build quantum applications like very long coherence times event at room temperature, facility to access and couple to C¹³ nuclear spins and finally the ability to couple to photons that can carry quantum information over large distances that can enable quantum networks.

In this webinar, we will address the key advancements in the optimisation of processes for the fabrication of these powerful quantum devices.

Agenda

Abstracts

Optimising Diamond for Quantum Technologies
Dr Matthew Markham, Element Six Ltd. Global Innovation Centre

Quantum technologies is attracting significant investment due to the range of potential applications, yet behind any new technology are enabling materials. Diamond is one such material, which has been used in demonstrations ranging from magnetic sensing to quantum computing. In order for these diamond quantum technologies to move from laboratory-based demonstrations to commercial products requires material with repeatable properties that can be produced with scale.

This presentation will focus on the optimisation of diamond materials developed for magnetic sensing and quantum information processing. The presentation will briefly discuss how CVD diamond is synthesised and then go on to discuss the characterisation of NV materials demonstrating repeatable properties such as T2* and intrinsic strain in a range of materials.

Plasma Etching for Diamond-based Quantum Technologies
Colin Welch, Oxford Instruments Plasma Technology

Application of diamond nitrogen vacancies for quantum computing, communication and sensing requires robust surface and feature preparation processes. This talk will feature our newly developed etching processes for thinning of diamond membranes while preserving the activity of laser-activated nitrogen-vacancy centres (NVCs). In addition, examples of diamond etching processes for building light manipulating structures via feature creation on surfaces (lenses, photonic crystals) will be shown.

Engineering Diamond Devices for Scalable Quantum Networks
Prof. Jason Smith, Oxford University

Many proposed quantum information systems for communications and computing rely on the efficient transfer of information between optical and spin degrees of freedom. Diamond colour centres are excellent candidates for such interfaces, as they can combine highly coherent spin states coupled selectively to coherent optical transitions. Proof-of-concept experiments with nitrogen-vacancy (NV) centres have shown that spins can be entangled over km distances and quantum information stored for over a minute.

In order to advance towards practical devices, two of the principal challenges are the engineering of diamond materials to allow large scale parallelisation, and the engineering of devices to improve the spin-photon coupling efficiency.

In this talk, I will discuss recent efforts directed at both of these challenges, focusing on the controlled writing of colour centres into diamond and the construction of optical microcavity devices to control spontaneous emission.