Portable Quantum Sensor for Simultaneous Temperature and Magnetic Field Measurement Using Nitrogen-Vacancy Ensembles in Diamond

Nitrogen-vacancy (NV) centres in diamond are promising quantum systems for sensing applications due to their quantum coherence, optical addressability, and robust performance even at room temperature [1], [2]. These properties allow for the precise measurement of environmental parameters, such as magnetic fields [2], electric fields, strain, and temperature [1]–[4]. This work focuses on a portable multisensing platform based on NV centres, examining its performance across a temperature range of -20°C to 120°C [2]. Understanding the temperature dependence of the spectral features of NV centres is crucial not only to assess its capabilities for multisensing, but also for optimising the device for diverse operating conditions and for ensuring the precision and reliability of quantum measurements [3]. While many studies focus on low temperatures or individual NV centres, this work focuses on an ensemble of NV centres at relatively high temperatures, which is more suitable for portable sensors [1], [5]. This work is novel as it provides a comprehensive study of a portable NV -based multisensor's performance at relatively high temperatures, crucial for real-world applications [1].