I am a PhD student in the EPR and Diamond Research Group at the University of Warwick under the supervision of Prof Mark Newton. I graduated from The University of Warwick in 2011 with a Masters in Physics (MPhys).

Project Summary

My research focuses on understanding and controlling the production mechanisms of the Negative nitrogen vacancy (NV^-) centre in diamond. The spin state of a single negatively charged NV^- centre in diamond can be detected optically at room temperature. An individual NV^- centre can be viewed as a basic unit of a quantum computer, leading to novel applications in quantum information processing.

'Grown in' NV

Even the very purest diamond grown by chemical vapour deposition (CVD) contains some nitrogen impurities; if desired the amount of nitrogen can be increased. If a vacancy is formed next to a nitrogen atom during synthesis a 'grown in' NV⁰ centre is formed. With a little redistribution of charge it can become an NV^- centre. NV^- formed in this way has been found to have very good properties; the coherence times of the electron spin are very long. The downside is that there is no control over where these centres form.

Ion implanted NV

Instead of producing the NV^- centres during growth they can be introduced later. One way of doing this is to implant nitrogen ions into a very pure diamond lattice. As the nitrogen is implanted it will collide with carbon atoms of the diamond lattice, displacing them and creating interstitials and vacancies. When the diamond is heated above 600^oC the vacancies can migrate through the lattice. If one meets the nitrogen atom that created it an NV^- centre can form. The advantage of this method is the ability to form arrays of addressable NV^-. Unfortunately however the coherence times are inferior to the grown in NV^- centres due to the effect of the residual damage to the lattice.

Raman / Photoluminescence spectrometers

We have two Renishaw PL/Raman inVia spectrometers in our lab equipped with 325, 442, 514, 633 and 785 nm lasers. I am in charge of booking requests for the spectrometers and looking after users. More information is available here. The booking page for the systems is here.

Teaching

I demonstrate and mark the 2^nd year electronics lab. In the lab the students build a regulated DC power supply on strip board. In 16 hours the students have to overcome the challenges of soldering and circuit layout but mostly determining why the circuit does not give the desired result!

Papers

D.I. Woodward, R. Dittmer, W. Jo, D. Walker, D.S. Keeble, M.W. Dale, J. Rödel, P.A. Thomas, Investigation of the depolarisation transition in Bi-based relaxor ferroelectrics. J. Appl. Phys. 115, 114109 (2014).

Conferences and workshops

July 2014 - 65^th Diamond Conference, University of Warwick, presentation 'In-situ uniaxial stressed electron paramagenetic resonance'

July 2014 - 65^th Diamond Conference, University of Warwick, poster presentation 'Photochromism in irradiated and annealed Ib diamond'

April 2014 - iMR-CDT research conference, University of Dundee, presentation 'GPa uniaxial stress of single crystal samples'

April 2014 - 47^th Royal Society of Chemistry ESR Conference, University of Dundee, poster presentation 'GPA uniaxial stress of single crystal samples'

July 2013 - 64^th Diamond conference, University of Warwick, poster presentation 'Neutron irradiation and the production of the negative nitrogen-vacancy centre'

April 2013 - iMR-CDT advanced workshop II, University of Warwick

April 2013 - 46^th Royal Society of Chemistry ESR Conference, University of Warwick, poster presentation 'Improving the accuracy of quantitative EPR'

February 2013 - 18^th Hasselt Diamond Workshop 2013, Hasselt, Belgium, poster presentation 'Neutron irradiation and the production of the negative nitrogen-vacancy centre'

January 2013 - 6^th EFEPR winter school, Rehovot, Israel

July 2012 - 63^rd De Beers Diamond conference, University of Warwick, poster presentation 'Investigation into the production of the negative nitrogen-vacancy centre in type Ib diamond'

March 2012 - iMR-CDT advanced workshop, University of Warwick

December 2011 - iMR-CDT kick-off workshop, University of Warwick

July 2011 - 62^nd De Beers Diamond Conference, University of Warwick

Write to:

EPR & Diamond Group
Department of Physics
University of Warwick
CV4 7AL

Contact Details:

Office: F16
Tel: +44(0) 24 7615 0813
m.w.dale@warwick.ac.uk