Prof James (aka John) Davies
Profile
My research has centred on the optical and magnetic spectroscopy of condensed matter, with special emphasis on:
- the magnetic properties of insulating solids
- on the processes of light emission from semiconductors
- on the magnetic behaviour of charge carriers and excitons under quantum confinement in semiconductor heterostructures
The principal experimental methods have been those of magnetic resonance (ESR, ENDOR, ODMR) and optical spectroscopy (particularly photoluminescence and resonance Raman scattering). The work has involved collaboration with several other institutions, both in the UK and abroad, with especially strong interactions with Russian, German and French research groups, and is supported by EPSRC and the Royal Society.
My current research is concentrated (in collaboration with Dr Daniel Wolverson, Dr Lowenna Smith and Dr Stephen Bingham) on the remarkable changes that excitons undergo as they acquire kinetic energy in quantum wells and on optically detected magnetic resonance and spin-flip Raman scattering studies of wide bandgap heterostructures such as GaN, ZnO and ZnSe.
Publications
Davies, J.J., 2013. Magnetic resonance and the structure of magnesium acceptors in gallium nitride. Physical Review B, 87 (23), 235208.
Rice, C., Smith, L. C., Davies, J. J., Wolverson, D., Wiater, M., Karczewski, G. and Wojtowicz, T., 2012. Exchange interactions in Cd1-xMnxTe wide quantum wells. Physical Review B, 86 (15), 155318.
Wolverson, D., Smith, L. C., Bingham, S. J. and Davies, J. J., 2012. Coherent Raman spectroscopy of the quantum-entangled exciton-Mn2+ state in CdTe. Physical Review B, 86 (15), 155209.
Rice, C., Smith, L. C., Davies, J. J., Wolverson, D., Wiater, M., Karczewski, G. and Wojtowicz, T., 2012. Exciton-Mn exchange interactions as a function of translational wavevector in Cd1-xMnxTe quantum wells. Physica Status Solidi (C), 9 (8-9), pp. 1826-1829.
Kochereshko, V. P., Davies, J. J., Smith, L. C., Wolverson, D., Mariette, H., Boukari, H., Wiater, M., Karczewski, G. and Wojtowicz, T. J., 2011. Effects of motion on exciton magnetic properties. Physica Status Solidi (C) Current Topics in Solid State Physics, 8 (4), pp. 1173-1177.
Smith, L. C., Davies, J. J., Wolverson, D., Boukari, H., Mariette, H., Kochereshko, V. P. and Phillips, R. T., 2011. Wave-vector dependence of magnetic properties of excitons in ZnTe. Physical Review B, 83 (15), 155206.
Loginov, D. K., Kochereshko, V. P., Cox, R. T., Besombes, L., Mariette, H., Davies, J. J., Wolverson, D. and Smith, L. C., 2010. Excitonic polaritons in transverse magnetic fields. Physica Status Solidi B-Basic Solid State Physics, 247 (6), pp. 1528-1530.
Davies, J., Smith, L., Wolverson, D., Kochereshko, V. P., Cibert, J., Mariette, H., Boukari, H., Wiater, M., Karczewski, G., Wojtowicz, T., Gust, A., Kruse, C. and Hommel, D., 2010. Excitons in motion in II-VI semiconductors. Physica Status Solidi B-Basic Solid State Physics, 247 (6), pp. 1521-1527.
Davies, J. J., Smith, L. C., Wolverson, D., Gust, A., Kruse, C., Hommel, D. and Kochereshko, V. P., 2010. Motion-enhanced magnetic moments of excitons in ZnSe. Physical Review B, 81 (8), 085208.
Loginov, D. K., Kochereshko, V. P., Platonov, A. V., Davies, J. J., Wolverson, D., Smith, L. C., Cox, R. T., Cibert, J. and Mariette, H., 2009. Exciton polaritons in quantum wells in a transverse magnetic field. Physics of the Solid State, 51 (8), pp. 1649-1655.
Koudinov, A., Kusrayev, Y., Wolverson, D., Smith, L., Davies, J., Karczewski, G. and Wojtowicz, T., 2009. Giant modulation of resonance Raman scattering from (Cd,Mn)Te quantum wells by secondary illumination. Physical Review B, 79 (24), 241310.
Kochereshko, V. P., Platonov, A. V., Davies, J. J., Wolverson, D., Smith, L. C., Cox, R. T., Cibert, J. and Mariette, H., 2009. Motional enhancement of the exciton magnetic moment. Physica Status Solidi (C), 6 (2), pp. 512-515.
Smith, L. C., Davies, J. J., Wolverson, D., Crampin, S., Cox, R. T., Cibert, J., Mariette, H., Kochereshko, V. P., Wiater, M., Karczewski, G. and Wojtowicz, T., 2008. Motion-dependent magnetic properties of excitons in CdTe. Physical Review B, 78 (8), 085204.
Kochereshko, V. P., Smith, L., Davies, J., Cox, R. T., Platonov, A., Wolverson, D., Boukari, H., Mariette, H., Cibert, J., Wiater, M., Wojtowicz, T. and Karczewski, G., 2008. Excitons in motion: universal dependence of the magnetic moment on kinetic energy. Physica Status Solidi B-Basic Solid State Physics, 245 (6), pp. 1059-1063.
Smith, L., Davies, J., Wolverson, D., Lentze, M., Geurts, J., Wojtowicz, T. and Karczewski, G., 2008. Dependence of multiple Mn2+ spin-flip Raman scattering in quantum wells on the magnetic field direction. Physical Review B, 77 (11), 115341.
Kochereshko, V. P., Platonov, A. V., Loginov, D. K., Davies, J., Wolverson, D., Smith, L. C., Boukari, H., Cox, R. T., Cibert, J. and Mariette, H., 2008. Motional enhancement of the exciton magnetic moment. Semiconductor Science and Technology, 23 (11), p. 114011.
