The negatively-charged nitrogen vacancy (NV−) centre in diamond is a remarkable optical quantum sensor for a range of applications including, nanoscale thermometry, magnetometry, single photon generation, quantum computing, and communication. However, to date the performance of these techniques using NV− centres has been limited by the thermally-induced spectral wandering of NV− centre photoluminescence due to detrimental photothermal heating. Here we demonstrate that solid-state laser refrigeration can be used to enable rapid (ms) optical temperature control of nitrogen vacancy doped nanodiamond (NV−:ND) quantum sensors in both atmospheric and \textit{in vacuo} conditions. Nanodiamonds are attached to ceramic microcrystals including 10\% ytterbium doped yttrium lithium fluoride (Yb:LiYF4) and sodium yttrium fluoride (Yb:NaYF4) by van der Waals bonding. The fluoride crystals were cooled through the efficient emission of upconverted infrared photons excited by a focused 1020 nm laser beam. Heat transfer to the ceramic microcrystals cooled the adjacent NV−:NDs by 10 and 27 K at atmospheric pressure and ∼10−3 Torr, respectively. The temperature of the NV−:NDs was measured using both Debye-Waller factor (DWF) thermometry and optically detected magnetic resonance (ODMR), which agree with the temperature of the laser cooled ceramic microcrystal. Stabilization of thermally-induced spectral wandering of the NV− zero-phonon-line (ZPL) is achieved by modulating the 1020 nm laser irradiance. The demonstrated cooling of NV−:NDs using an optically cooled microcrystal opens up new possibilities for rapid feedback-controlled cooling of a wide range of nanoscale quantum materials.
@article{arxiv.2007.15247,
title = {Solid-state laser refrigeration of nanodiamond quantum sensors},
author = {Anupum Pant and R. Greg Felsted and Alexander B. Bard and Xiaojing Xia and Siamak Dadras and Kamran Shayan and Danika R. Luntz-Martin and Donald Mannikko and Ilia M. Pavlovetc and Stefan Stoll and Masaru Kuno and A. Nick Vamivakas and Peter J. Pauzauskie},
journal= {arXiv preprint arXiv:2007.15247},
year = {2020}
}