Ultra-sensitive hybrid diamond nanothermometer

Abstract

Nitrogen-vacancy (NV) centers in diamond are promising quantum sensors for their long spin coherence time under ambient conditions. However, their spin resonances are relatively insensitive to non-magnetic parameters such as temperature. A magnetic-nanoparticle-nanodiamond hybrid thermometer, where the temperature change is converted to the magnetic field variation near the Curie temperature, was demonstrated to have enhanced temperature sensitivity ($11{\rm{\;mK\;H}}{{\rm{z}}^{ - 1/2}}$) [Phys. Rev. X 8, 011042 (2018)], but the sensitivity was limited by the large spectral broadening of ensemble spins in nanodiamonds. To overcome this limitation, here we show an improved design of a hybrid nanothermometer using a single NV center in a diamond nanopillar coupled with a single magnetic nanoparticle of copper-nickel alloy, and demonstrate a temperature sensitivity of $76{\rm{\;\mu K\;H}}{{\rm{z}}^{ - 1/2}}$. This hybrid design enables detection of 2 millikelvin temperature changes with temporal resolution of 5 milliseconds. The ultra-sensitive nanothermometer offers a new tool to investigate thermal processes in nanoscale systems.

Preparations and applications of single color centers in diamond

“…This, in turn, would boost the development of NV center in practical applications, particularly the quantum network required high integration. Quantum sensing, however, remains the most promising application due to the fragile energy level that offers exceptional sensitivities to external factors, with excellent achievements in detecting magnetic field [95], temperature [47], pressure [48] and other physical quantity [143,144]. Moreover, the biological harmless property of diamond renders the NV center valuable in biological applications.…”

“…For example, diamond nanocrystals can effectively eliminate the reflection loss of color center fluorescence in the bulk diamond, thus enhancing the efficiency of fluorescence collection efficiency [44,45]. Moreover, the biocompatibility of nanodiamond combined with the stable fluorescence of NV center enables quantum sensing in living cell [8,[46][47][48].…”

“…The NV center is also used as the nanoscale sensor of pressure and temperature, because a change of an external factor would generate the strain in the diamond crystal and induce the lattice distortion, which shifts the resonate peak in the ODMR spectrum. Experimentally, a temperature sensitivity of 76 μK/√Hz [47] and a pressure resolution of 0.6 MPa/√Hz [48] were achieved in the terms of NV-based thermometer and manometer, respectively. In the field of thermometry, this kind of thermometer has been applied in the living cell [108] on the basis of the non-invasive peculiarity to organisms as we described above, which encouraged the study about thermogenesis to learn more about biological mechanisms.…”

Toward Quantitative Bio-sensing with Nitrogen–Vacancy Center in Diamond

“…This is achieved by converting temperature measurement into more sensitive magnetic field sensing with NV centers, especially near the ferromagnetic–paramagnetic transition temperature accompanied by huge magnetization changes. In addition, the sensitivity could be further improved (76 μK Hz –1/2 ) by using a single NV center in a diamond nanopillar coupled with a single MNP . Following a similar strategy, Zhang et al constructed another hybrid nanothermometer by employing temperature-responsive hydrogels as a “spacer” between the NDs (with NV centers) and MNPs.…”

Enhanced quantum sensing with room-temperature solid-state masers

“…Quantum sensing with solid-state systems finds broad applications in diverse areas ranging from material and biomedical sciences to fundamental physics. Several solid-state spin sensors [1][2][3] have been developed, facilitating the ultra-sensitive detection of physical quantities such as magnetic and electric fields [1,[4][5][6][7] and temperature [8,9]. Exploiting collective behaviour of non-interacting spins holds the promise of pushing the detection limit to even lower levels [4], while to date, those levels are scarcely reached due to the broadened linewidth and inefficient readout of solid-state spin ensembles [1].…”