Figure 1. Graphene–NVC hybrid optomechanical device.

(a) Energy diagrams of an optical emitter and graphene at the K point of the Brillouin zone (Dirac cone). For small separations d_G–NVC<50 nm, the relaxation of the excited emitter is predominantly due to near-field dipole–dipole interaction by excitation of electron–hole pairs in graphene. (b) Sketch of the hybrid optomechanical device. The graphene resonator is driven and displaced electrostatically by d.c. and a.c. voltages V_g^dc and δV_g, while its nanomotion is measured optically via the emitter using single-photon counters (APD) and by interferometry. (c) False colour AFM topology of nanodiamonds (red) deposited in the centre of a hole etched into SiO₂. (d) False colour scanning electronic micrograph (SEM) of arrays of hybrid graphene devices. The labelled hole corresponds to c. Graphene is closely suspended over the nanodiamonds (0–50 nm) and clamped at the edges of the holes by Vander Waals interactions. (e) False colour confocal reflection map of the same device shown in c at T=3 K. At each laser position, both emission and a mechanical spectrum are recorded, thus providing a spatial map of the NVC emission (f), and the extracted mechanical resonance frequency f_m (g).