In the early 1980s Aspect et al. demonstrated the non–locality of quantum mechanics, by measuring correlations between polarisation states. Since then, using photonpairs generated by down–conversion, entanglement has been observed for many variables, including the transverse position of one photon with the linear momentum of its partner. One variant of these experiments is "ghost diffraction" and "ghost imaging" in which an aperture placed in one beam of a pair of entangled beams creates its diffraction pattern or image only in the coincidence count rate recorded between the two beams.
Quantum entanglement is a coherent process, the coincidence count rate depending on both the intensity and phase structure of the detected photons. Spatial phase entanglement was demonstrated, for example, by Zeilinger et al. who observed correlations in the orbital angular momentum of down–converted photons (c.f. polarization and spin angular momentum). While this work used fixed holograms to control the phase–structure of the light, groups from Glasgow and Strathclyde universities have recently achieved dynamic control of the holograms using spatial light modulators (SLMs). These devices can be rapidly reconfigured to observe entanglement in both angular and linear states and their conjugate variables.
This PhD project is part of a major new EPSRC–funded collaboration between Heriot–Watt, Glasgow and Strathclyde Universities in quantum or ghost imaging. This challenging project will research many aspects of this fascinating phenomenon, including the construction of a full demonstrator quantum imaging system. This PhD project offers exciting opportunities for experimental work in close collaboration with the other partner institutions, as well as a chance to explore the theoretical possibilities presented by this remarkable and practical example of photon correlation and entanglement.
A talented and motivated student is required for the EPSRC studentship associated with this project. This studentship is also open to appropriately qualified non–UK residents.
If you are interested in a PhD place, please email Prof Gerald S. Buller