Thermal-demagnetization-enhanced hybrid fiber-based thermometer coupled with nitrogen-vacancy centers

Abstract

Nitrogen-vacancy centers in diamond are attractive as quantum sensors owing to their remarkable optical and spin properties under ambient conditions. Here we experimentally demonstrated a hybrid fiber-based thermometer coupled with nitrogen-vacancy center ensemble and a permanent magnet, where the temperature sensitivity was improved by converting the temperature variation to the magnetic field change based on the thermal-demagnetization of the permanent magnet. We have achieved both large temperature working range (room temperature to 373 K) and millikelvin sensitivity (1.6 mK/ √ Hz), nearly 6-fold improvement compared with conventional technique. This stable and compact hybrid thermometer will enable a wide range of applications for large-area detection and imaging with high temperature sensitivity.A stable and compact thermometer capable of millikelvin resolution over a large temperature range could provide a powerful tool in many areas of physical, chemical, and biological researches 1 . Lots of promising approaches to local temperature sensing are being explored at present, including Raman spectroscopy 2 , scanning probe microscopy 3 , and fluorescence-based measuremnets 4 using nanoparticles and organicdyes 5 . However, many of these methods are limited by drawbacks such as low sensitivity and systematic errors due to fluctuations in the fluorescence rate and the local environment 1,6 .In recent years, the negatively charged nitrogen-vacancy (NV) center, a point defect in diamond, provides a promising system to realize practical quantum devices which have been successfully applied to a wide range of applications in quantum information processing and sensing in both physical and life sciences 7 . These applications of the NV center are based upon its remarkable optical and spin properties: bright optical fluorescence, long-lived spin coherence, and mature optical polarization and readout at room temperature 8 . For the NV-based temperature sensing, the techniques with modified spin-echo sequence 1 and high-order Carr-Purcell-Meiboom-Gill method 9,10 have achieved a sensitivity of 10 mK/ √ Hz. A nano-thermometer composed of NV centers and a magnetic nanoparticle has been experimentally demonstrated 11 , where an optimal temperature sensitivity of 3 mK/ √ Hz has been obtained by the critical magnetization of the magnetic nanoparticle near Cuire temperature. Moreover, the recently developed fiber-optic probes coupled with NV centers were shown to enable a temperature measurement with a 20 mK accuracy using optically detected magnetic resonance (ODMR) [12][13][14] .In order to further enhance the sensitivity of the NV thera) Electronic mometer for practical application, here, we proposed a hybrid fiber-based thermometer coupled with NV center ensembles and a permanent magnet. By converting the temperature variation to a magnetic field change 11,15 of the permanent magnet, this thermometer can achieve a high sensitivity of 1.6 mK/ √ Hz and a large temperature working range, where the permanent magnet is served as...

Diamond quantum thermometry: from foundations to applications

“…these reports, quantum-enhanced high-temperature sensitivity of diamond NV centres was demonstrated using sophisticated quantum spin control protocols [7][8][9]. With this wide range of temperature responsivity, spin-based thermometry has been demonstrated to work in the range of 150-1000 K [25,74,77,78]. Three types of measurement protocols can be used to read the temperature-dependent frequency shift of ODMR in the NV centres: (i) continuous-wave (CW) ODMR spectral measurement method, (ii) multipoint ODMR method, and (iii) pulsed ODMR method.…”

Simultaneous temperature and magnetic field measurements using time-division multiplexing

“…Nitrogen-vacancy (NV) color centers are emerging solid-state quantum sensors that can measure several physical quantities using different detection protocols due to the influence of physical quantities variations such as magnetic field [1,2] , electric field [3] , temperature [4][5][6][7] , and stress [8] . With the advantages of high spatial and temporal resolution, high sensitivity, stable signal, and quantum performance at room temperature, NV color centers can provide an effective means of characterization in a variety of fields, including biomedicine [9] , dark matter [10] , electrochemical signals [11] , etc.…”

Correlative Fluorescence and Transmission Electron Microscopy Assisted by 3D Machine Learning Reveals Thin Nanodiamonds Fluoresce Brighter

“…Atom-like solid-state quantum emitters have excellent potential as nanosensors, offering high spatial resolution and minimized disturbance to the host. Among the quantum emitters available, nitrogen vacancy (NV) centers in fluorescent nanodiamonds (FNDs) have attracted immense interest owing to their room-temperature operation, exceptionally high photo- and chemical stability, and excellent biocompatibility. − Such advantages have seen FNDs utilized as sensors of local temperature, , electric and magnetic fields, − local crystallographic strain, and single molecules . Recently, detection of HIV with a sensitivity 5 orders of magnitude better than conventional gold nanoparticles has further demonstrated the potential of FNDs as highly competitive biosensors for medical diagnostics.…”