There is significant interest in potential experimental tests of macroscopic quantum effects, both to test potential modifications to quantum theory and to probe the quantum nature of gravity. A proposed platform with which to generate the required macroscopic quantum spatial superposition is a nanodiamond containing a negatively charged nitrogen vacancy (${ \text{ NV}}^{ -}$) centre. In this review, methods to fabricate nanodiamonds containing ${ \text{ NV}}^{ -}$ suitable for these quantum applications are discussed. The proposed probes of the macroscopic limits of quantum theory are presented along with the spin physics of the ${ \text{ NV}}^{ -}$ centre relevant to those tests.
Categories: quant-ph cond-mat.mes-hall physics.optics
