Burning and graphitization of optically levitated nanodiamonds in vacuum

Abstract

A nitrogen-vacancy (NV−) centre in a nanodiamond, levitated in high vacuum, has recently been proposed as a probe for demonstrating mesoscopic centre-of-mass superpositions and for testing quantum gravity. Here, we study the behaviour of optically levitated nanodiamonds containing NV− centres at sub-atmospheric pressures and show that while they burn in air, this can be prevented by replacing the air with nitrogen. However, in nitrogen the nanodiamonds graphitize below ≈10 mB. Exploiting the Brownian motion of a levitated nanodiamond, we extract its internal temperature (Ti) and find that it would be detrimental to the NV− centre’s spin coherence time. These values of Ti make it clear that the diamond is not melting, contradicting a recent suggestion. Additionally, using the measured damping rate of a levitated nanoparticle at a given pressure, we propose a new way of determining its size.

Electron spin resonance from NV centers in diamonds levitating in an ion trap

“…They provide efficient localization for neutral and charged particles and can work under liquid or atmospheric environnements. However the trap light that is scattered from the object means that excessive heating can be at work [6,7,9,10]. Furthermore, optical traps may quench the fluorescence of NV centers [7] and affect the electronic spin resonance contrast.Being able to trap diamonds hosting NV centers without light scattering could thus offer a better control of the spin-mechanical coupling and enlarge the range of applications of levitating diamonds.…”

An analytical model for the detection of levitated nanoparticles in optomechanics

“…Subsequently, these frequencies are used for parametric feedback cooling to actively control the motion of a levitated particle. [1][2][3]5,[8][9][10][11][12][13][14] As with other interferometric schemes, this system is well known for its high precision and resilience to noise. In optomechanical setups, this is further enhanced by a balanced detection system.…”

Tolerance in the Ramsey interference of a trapped nanodiamond

“…ρ th (0) = 1 2 d 2 β P th ( β) β β (|+1 +|−1 )( +1|+ −1|), (27) where β = (β x , β y , β z ) and P th ( β) is the Glauber P representation for the thermal state, …”

“…This immunity of the interference to thermal states hinges on the mass being trapped in a harmonic potential. We assume that anharmonic effects of the trapping potential will be avoided by feedback cooling of our oscillator to mK temperatures [25][26][27].…”