Low Nitrogen Microdiamond
Demanding quantum applications of fluorescent diamond requires NV centers with good spin properties such as long spin coherence (T2) times and high contrast. Paramagnetic nitrogen centers (P1) can degrade NV spin coherence and diminish performance. Fluorescent diamond particles are usually derived from Type Ib diamond particles containing 100-300 atomic ppm of nitrogen. The Low Nitrogen Fluorescent Microdiamond particles contain sub-50 ppm of nitrogen, and have NV centers with improved spin properties tailored for quantum sensing applications.
Figure 1: Micrograph of HPHT grown microparticles
Technical Characteristics
Particle Sizes
Currently available low nitrogen microparticles have nominal sizes of the 150 – 200 µm (Figure 1). The particles are synthesized via high pressure high temperature (HPHT) growth.
Nitrogen and NV Content
The nitrogen content was assessed with IR spectroscopy. Particles with three levels of nitrogen content are available. NV content in all samples is estimated to be < 3 ppm.
ODMR and T1 Relaxation Characterization
Continuous wave ODMR spectra are shown in Figure 2 and additional summary characteristics are collected in the table below.
NV centers in reduced nitrogen microparticles exhibit enhanced CW ODMR contrast as well as extended T1 relaxation times as compared to diamond particles with standard nitrogen content (ca. 100 ppm). The FMDLN1 series offers the highest contrast, while the FMDLN2 and FMDLN3 particles exhibit narrower ODMR linewidths (Figure 2).
NOTE: ODMR and T1 relaxation characteristics can be subject to measurement configurations and settings. All data presented were collected under green LED excitation providing approximately 3.4 mW/mm2 incident power density at 10x magnification. Microwave power was kept at -5 dBm (0.32 mW) for collection of ODMR spectra.
Figure 2: Continuous wave ODMR spectrum of FMDNVLN samples and a typical HPHT diamond sample with ca. 100 ppm nitrogen content.
Relevant Tables
Application Areas
NV Magnetometry
NV Thermometry
