Burning and graphitization of optically levitated nanodiamonds in vacuum.
Burning and graphitization of optically levitated nanodiamonds in vacuum.
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DOI：
10.1038/srep21633
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发表时间：
2016-02-22
影响因子：
4.6
通讯作者：
Barker PF
中科院分区：
文献类型：
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作者：
Rahman AT;Frangeskou AC;Kim MS;Bose S;Morley GW;Barker PF
悬浮在高真空中的纳米金刚石中的氮空位（NV−）中心最近被提出作为证明介观质心叠加和测试量子引力的探针。在这里，我们研究了含有NV -中心的光学悬浮纳米金刚石在亚大气压下的行为，并表明当它们在空气中燃烧时，可以通过用氮气代替空气来防止。然而，在氮气中，纳米金刚石在≈10 mB以下石墨化。利用悬浮纳米金刚石的布朗运动，我们提取了其内部温度（Ti），发现它会对NV -中心的自旋相干时间产生不利影响。钛的这些值清楚地表明，钻石没有熔化，这与最近的一种说法相矛盾。此外，利用测量悬浮纳米颗粒在给定压力下的阻尼率，我们提出了一种确定其尺寸的新方法。
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.