Towards a test of quantum gravity with a levitated nanodiamond containing a spin

Abstract

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 (NV − ) centre. In this review, methods to fabricate nanodiamonds containing 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 NV − centre relevant to those tests.