An integrated and scalable experimental system for nitrogen-vacancy ensemble magnetometry

Abstract

Nitrogen-vacancy (NV) centers in diamond are extremely promising solid-state spin quantum sensors for magnetic field in recent years. The rapid development of NV-ensemble magnetometry has put forward higher requirements for high-speed data acquisition, real-time signal processing and analyzing, etc. However, the existing commercial instruments are bulky and expensive, which brings extra complexity to the weak magnetic field detection experiment and hinders the practicality and miniaturization of NV-ensemble magnetometry. Here, we report on an integrated and scalable experimental system based on a field-programmable-gate-array (FPGA) chip assisted with high-speed peripherals for NV-ensemble magnetometry, which presents a compact and compatible design containing high-speed data acquisition, oscilloscopes, signal generator, spectrum analyzer, lock-in amplifier, proportional-integral-derivative feedback controller, etc. To verify its applicability and reliability in experiments, various applications, such as optical magnetic resonance detection, optical cavity locking, and lock-in NV magnetometry, are conducted. We further realize the pump-enhanced magnetometry based on NV center ensembles using the optical cavity. Through the flexible FPGA design approach, this self-developed device can also be conveniently extended into atomic magnetometer and other quantum systems.

The concentration estimation for ensemble of NV– color centers with spin coherent manipulation

“…1) Due to its stable excited emission fluorescence, ultra-long decoherence time at room temperature, simple spin energy level structure, 2,3) and reliable and convenient microwave manipulation technology as well as optical readout means, the negatively charged nitrogen-vacancy color center (NV − ) has become key to a new quantum sensing system with broad application prospects. 4,5) The number, concentration, and spatial distribution characteristics of NV − color centers in diamond directly affect its precision sensing characteristics and imaging quality, whereby the concentration and distribution of NV − centers in diamond have a direct impact on the sensitivity and resolution of the quantum sensor. [6][7][8] To give an estimation for NV − , a series of methods have been implemented.…”

Microcontroller-Optimized Measurement Electronics for Coherent Control Applications of NV Centers

“…The electronics include a switchable source for microwaves in the GHz range, a detector for photodiodes, a lock-in amplifier (LIA) with a low-pass filter for signal acquisition, a microcontroller for the output of pulse sequences, and the data acquisition from the LIA and the control of the microwave source. Research in this direction has been carried out already but does not show a completely integrated solution and is either limited to FPGA-based development boards or the simple plugging together of COTS modules [5][6][7]. Pulse sequences needed for various spin manipulation experiments can be programmed using a simple array and can be modified on the fly.…”