We have proposed schemes for testing the limits of quantum mechanics which rely on levitating nanodiamonds containing nitrogen-vacancy (NV-) centres. We would like to put the spin of an NV- centre into a superposition and then use an inhomogeneous magnetic field to translate this into a spatial superposition, so that the diamond tries out being in two places at once. The photo shows one of our levitated nanodiamonds as a green dot (due to the green laser light we are shining onto it). Angelo Frangeskou and Anis Rahman are working on this project which is a collaboration with the groups of Peter Barker and Sougato Bose (UCL), Myungshik Kim (Imperial) and Hendrik Ulbricht (Southampton).
More details are in our papers:
5. AC Frangeskou, ATMA Rahman, L Gines, S Mandal, OA Williams, PF Barker & GW Morley, Optical levitation of high purity nanodiamonds in vacuum without heating, arXiv:1608.04724 (2016)
4. C Wan, M Scala, GW Morley, ATMA Rahman, H Ulbricht, J Bateman, PF Baker, S Bose, MS Kim, Free Nano-Object Ramsey Interferometry for Large Quantum Superpositions, Physical Review Letters 117, 143003 (2016). Open access.
2. C Wan, M Scala, S Bose, AC Frangeskou, ATMA Rahman, GW Morley, PF Barker & MS Kim, Tolerance in the Ramsey interference of a trapped nanodiamond, Physical Review A 93, 043852 (2016), arXiv preprint
1. M Scala, MS Kim, GW Morley, PF Barker & S Bose, Matter-wave interferometry of a levitated thermal nano-oscillator induced and probed by a spin, Physical Review Letters 111, 180403 (2013), arXiv preprint