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arXiv · 1510.07555

Burning and graphitization of optically levitated nanodiamonds in vacuum

A. T. M. A. Rahman·A. Frangeskou·M. S. Kim·S. Bose·G. W. Morley·P. F. Barker
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Abstract

A nitrogen-vacancy (NV$^-$) center in a nanodiamond, levitated in high vacuum, has recently been proposed as a probe for demonstrating mesoscopic center-of-mass superpositions \cite{Scala2013, Zhang2013} and for testing quantum gravity \cite{Albrecht2014}. Here, we study the behavior of optically levitated nanodiamonds containing NV$^-$ centers 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 $\approx 10$ mB. Exploiting the Brownian motion of a levitated nanodiamond, we extract its internal temperature ($T_i$) and find that it would be detrimental to the NV$^-$ center's spin coherence time \cite{Toyli2012}. These values of $T_i$ make it clear that the diamond is not melting, contradicting a recent suggestion \cite{Neukirch2015}. Additionally, using the measured damping rate of a levitated nanoparticle at a given pressure, we propose a new way of determining its size.

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A. T. M. A. Rahman, A. Frangeskou, M. S. Kim, S. Bose, G. W. Morley, P. F. Barker. 2015-10-26. Burning and graphitization of optically levitated nanodiamonds in vacuum. https://doi.org/10.1038/srep21633

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