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). James March, Ben Wood and Guy Stimpson 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). Angelo Frangeskou and Anis Rahman previously worked on this.
More details are in our papers:
10. Julen S Pedernales, Gavin W Morley & Martin B Plenio, Motional Dynamical Decoupling for Matter-Wave Interferometry, arXiv:1906.00835 (2019).
9. Sougato Bose & Gavin W Morley, Matter and spin superposition in vacuum experiment (MASSIVE), arXiv:1810.07045 (2018).
8. Ryan J Marshman, Anupam Mazumdar, Gavin W Morley, Peter F Barker, Steven Hoekstra & Sougato Bose, Mesoscopic Interference for Metric and Curvature (MIMAC) & Gravitational Waves, arXiv:1807.10830 (2018).
7. AC Frangeskou, ATMA Rahman, L Gines, S Mandal, OA Williams, PF Barker & GW Morley, Pure nanodiamonds for levitated optomechanics in vacuum, New Journal of Physics 20, 043016 (2018). Open access, open data.
6. ATM Anishur Rahman, AC Frangeskou, PF Barker & GW Morley, An analytical model for the detection of levitated nanoparticles in optomechanics, Review of Scientific Instruments 89, 023109 (2018). Open access, open data.
5. S Bose, A Mazumdar, GW Morley, H Ulbricht, M Toroš, M Paternostro, A Geraci, P Barker, MS Kim & G Milburn, A Spin Entanglement Witness for Quantum Gravity, Physical Review Letters 119, 240401 (2017), arXiv preprint. Highlighted in popular press including PRL Synopsis, New Scientist, Quanta and The Atlantic.
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