Graduate Research: Quantum Physics to the Rescue

by Ketaki Patel on 7 October 2014

Before I came to Cambridge, I completed a BEng in Electronic Engineering with Communications at the University of Sheffield. I was part of the first cohort of students enrolled at the Doctoral Training Centre in Photonics Systems Development, where study begins with a one year MRes course, delivered jointly by the Cambridge Department of Engineering and University College London. This meant that I spent a considerable amount of time in London, not only attending lectures, but also carrying out a research project. Although the travelling was arduous, the year gave me a good insight into photonics systems and prepared me well for the PhD I subsequently undertook. During the PhD, I developed an interest in Intellectual Property, and I now aim to pursue a career in Patent Law.

My PhD research was in quantum cryptography, a field of physics using the principles of quantum physics for the development of secure data transmission systems. In our everyday lives, we take it for granted that data communications are secure: for example, when we make a bank transfer online or complete an online purchase. However, these transactions are susceptible to third-party attacks, and the purpose of my research has been to improve the way in which we protect them. Quantum cryptography, and the novel technique of Quantum Key Distribution (QKD), provides quantifiable security for personal data. It also enables us to identify the presence of any eavesdropper or hacker trying to intercept the “key”.

Currently, there are practical challenges in implementing the technology of quantum cryptography within existing data transmission networks, and it has in the past required dedicated optical fibres. My research focussed on characterising and optimising the performance of optoelectronics devices for the quantum system, so that this system could be integrated into existing optical fibre data transmission networks. I have helped to improve understanding of the technology and formulated various possibilities for adapting it to make it compatible with existing optical networks. The PhD has resulted in international conference presentations and publications in high-impact, peer-reviewed, journals, as well as a press release reported by the BBC and by the New York Times. More importantly, it will assist others to build secure infrastructures for information transfer, with implications for many day-to-day processes such as internet transactions.

I obtained an Industrial CASE studentship offered by the University of Cambridge and Toshiba Research Europe Ltd. I carried out most of the experimental work in Toshiba’s Cambridge Research Laboratory in the Cambridge Science Park. I was jointly supervised by Professor Richard Penty from the Department of Engineering and Dr Andrew Shields from Toshiba. Undertaking a PhD in the industrial sector gave me the opportunity to experience a normal working environment; having close links to the academic world allowed me to make use of available facilities and equipment within the university. This integrated training experience was challenging but equipped me with new skills and expertise. I have been actively involved in cutting edge research and gained a wider understanding of applied research.

Lucy Cavendish has also offered excellent support throughout my PhD. The College has given me a place to socialise, and it provided financial assistance on various occasions, including helping to fund my attendance at international conferences. My Tutor, Dr Orsola Rath Spivack, was a great source of advice and encouragement throughout my studies and really helped me to get through