image: Professor Richard Curry and the Platform for Nanoscale Advanced Materials Engineering tool used to place single atoms of tin into diamond. Credit: University of Manchester.
Credit: University of Manchester.
A new study led by researchers at the Universities of Oxford, Cambridge and Manchester has achieved a major advance in quantum materials, developing a method to precisely engineer single quantum defects in diamond—an essential step toward scalable quantum technologies. The results have been published in the journal Nature Communications.
Using a new two-step fabrication method, the researchers demonstrated for the first time that it is possible to create and monitor, ‘as they switch on’, individual Group-IV quantum defects in diamond—tiny imperfections in the diamond crystal lattice that can store and transmit information using the exotic rules of quantum physics. By carefully placing single tin atoms into synthetic diamond crystals and then using an ultrafast laser to activate them, the team achieved pinpoint control over where and how these quantum features appear. This level of precision is vital for making practical, large-scale quantum networks capable of ultra-secure communication and distributed quantum computing to tackle currently unsolvable problems.
Study co-author Professor Jason Smith, Department of Materials (University of Oxford) said: ‘This breakthrough gives us unprecedented control over single tin-vacancy colour centres in diamond, a crucial milestone for scalable quantum devices. What excites me most is that we can watch, in real time, how the quantum defects are formed.’
Specifically, the defects in the diamond act as spin-photon interfaces, which means they can connect quantum bits of information (stored in the spin of an electron) with particles of light. The tin-vacancy defects belong to a family known as Group-IV colour centres—a class of defects in diamond created by atoms such as silicon, germanium, or tin.
Group-IV centres have long been prized for their high degree of symmetry, which gives them stable optical and spin properties, making them ideal for quantum networking applications. It is widely thought that tin-vacancy centres have the best combination of these properties—but until now, reliably placing and activating individual defects was a major challenge.
The researchers used a focused ion beam platform—essentially a tool that acts like an atomic-scale spray can, directing individual tin ions into exact positions within the diamond. This allowed them to implant the tin atoms with nanometre accuracy—far finer than the width of a human hair.
To convert the implanted tin atoms to tin-vacancy colour centres, the team then used ultrafast laser pulses in a process called laser annealing. This process gently excites tiny regions of the diamond without damaging it. What made this approach unique was the addition of real-time spectral feedback—monitoring the light coming from the defects during the laser process. This allowed the scientists to see in real time when a quantum defect became active and adjust the laser accordingly, offering an unprecedented level of control over the creation of these delicate quantum systems.
Study co-author Dr Andreas Thurn (University of Cambridge) said: ‘What is particularly remarkable about this method is that it enables in-situ control and feedback during the defect creation process. This means we can activate quantum emitters efficiently and with high spatial precision - an important tool for the creation of large-scale quantum networks. Even better, this approach is not limited to diamond; it is a versatile platform that could be adapted to other wide-bandgap materials.’
Moreover, the researchers observed and manipulated a previously elusive defect complex, termed “Type II Sn”, providing a deeper understanding of defect dynamics and formation pathways in diamond.
Study co-author Professor Richard Curry (University of Manchester) said: “This work unlocks the ability to create quantum objects on demand, using methods that are reproducible and can be scaled up. This is a critical step in being able to deliver quantum devices and allow this technology to be utilised in real-world commercial applications.”
Notes to editors:
For interviews and media requests, contact:
University of Oxford: Caroline Wood Tel: 01865 280534 Email: caroline.wood@admin.ox.ac.uk
University of Cambridge: Vanessa Bismuth Tel: 01223 336 031
University of Manchester: Jessica Marsh, Media Relations Officer Tel: 07780281312 Email: Jessica.marsh@manchester.ac.uk
The study ‘Laser Activation of Single Group-IV Colour Centres in Diamond’ has been published in Nature Communications: https://www.nature.com/articles/s41467-025-60373-5
About the University of Oxford
Oxford University has been placed number 1 in the Times Higher Education World University Rankings for the ninth year running, and number 3 in the QS World Rankings 2024. At the heart of this success are the twin-pillars of our ground-breaking research and innovation and our distinctive educational offer.
Oxford is world-famous for research and teaching excellence and home to some of the most talented people from across the globe. Our work helps the lives of millions, solving real-world problems through a huge network of partnerships and collaborations. The breadth and interdisciplinary nature of our research alongside our personalised approach to teaching sparks imaginative and inventive insights and solutions.
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About the University of Cambridge
The University of Cambridge is one of the world’s leading universities, with a rich history of radical thinking dating back to 1209. Its mission is to contribute to society through the pursuit of education, learning and research at the highest international levels of excellence.
The University comprises 31 autonomous Colleges and over 100 departments, faculties and institutions. Its 24,000 students include around 9,000 international students from 147 countries. In 2023, 73% of its new undergraduate students were from state schools and more than 25% from economically disadvantaged backgrounds.
Cambridge research spans almost every discipline, from science, technology, engineering and medicine through to the arts, humanities and social sciences, with multi-disciplinary teams working to address major global challenges. In the Times Higher Education’s rankings based on the UK Research Excellence Framework, the University was rated as the highest scoring institution covering all the major disciplines.
A 2023 report found that the University contributes nearly £30 billion to the UK economy annually and supports more than 86,000 jobs across the UK, including 52,000 in the East of England. For every £1 the University spends, it creates £11.70 of economic impact, and for every £1 million of publicly-funded research income it receives, it generates £12.65 million in economic impact across the UK.
The University sits at the heart of the ‘Cambridge cluster’, in which more than 5,000 knowledge-intensive firms employ more than 71,000 people and generate £21 billion in turnover. Cambridge has the highest number of patent applications per 100,000 residents in the UK. www.cam.ac.uk
About The University of Manchester
The University of Manchester is recognised globally for its pioneering research, outstanding teaching and learning, and commitment to social responsibility. The Russell Group institution is ranked the 6th best university in the UK and 52nd in the world (Academic Ranking of World Universities). A truly international university, its community includes more than 44,000 students, 12,000 staff, and 550,000 alumni from 190 countries. Together, they are tackling the world’s biggest challenges – the University’s social and environmental impact is ranked in the top ten globally (Times Higher Education Impact Rankings). The University is a powerhouse of research and discovery; 26 Nobel laureates are among its former staff and students; and it was ranked fifth for research power – the quality and scale of research and impact – in the UK government’s Research Excellence Framework (REF) 2021. The institution is the most popular in the UK for undergraduate applications (UCAS 2023 cycle), and it is the most targeted university by the UK’s leading employers (The Graduate Market, 2024). Learn more at www.manchester.ac.uk
Journal
Nature Communications
Article Title
Laser activation of single group-IV colour centres in diamond