NV-Center ODMR Level Diagram (2D)

Sensor Controls

Magnetic field B 0.0 mT

MW sweep speed 0.12 GHz/s

MW drive power 70 %

Laser power 1.5 mW

Lattice temperature 300 K

Live Readout

MW frequency

2.870 GHz

Fluorescence

100 %

p(m₀)

100 %

p(m₊₁)+p(m₋₁)

0 %

Zeeman splitting Δf → inferred B

Δf = 0 MHz → B = 0.0 mT

How it works

Instead of a static lookup formula, this 2D version integrates the actual population rate equations of the NV ground-state spin triplet (m_s=0, +1, -1) as an ODE, live, every frame:

dp0/dt  = -k+(p0-p+1) -k-(p0-p-1) +kopt(p+1+p-1) -krelax(p0-1/3)
dp+1/dt =  k+(p0-p+1) -kopt·p+1 -krelax(p+1-1/3)
dp-1/dt =  k-(p0-p-1) -kopt·p-1 -krelax(p-1-1/3)

k± are microwave-driven transfer rates, Lorentzian in detuning from f± = D ± γB (D ≈ 2.870 GHz, γ/2π ≈ 28.0 MHz/mT); k_opt is the laser's spin-polarizing rate (saturates with power); k_relax is thermal spin-lattice relaxation (faster — shorter T₁ — at higher temperature). Because this is a real dynamical system rather than an instantaneous formula, sweeping the microwave faster than the populations can respond measurably shrinks the ODMR dip — a genuine transit-time effect you can see by cranking the sweep speed slider.

Drag the compass needle in the diagram (or use the slider) to set B directly — the two dips split apart exactly as Δf = 2γB, letting you read the field back out of the spectrum, the working principle of a diamond quantum magnetometer.

B field — sets the true Zeeman splitting between m_±1 sublevels.
MW drive power — how strongly the microwave couples m₀ to m_±1 at resonance.
Sweep speed — how fast the drive frequency scans; too fast blurs/shrinks the dips.
Laser power — optical spin-polarization rate into m₀ (with saturation).
Temperature — raises relaxation rate, broadening and shallowing the dips.

Optical pump (laser) Fluorescence decay MW drive (resonant)

Drag the compass needle to set B

ODMR spectrum · dynamic fluorescence vs. microwave frequency2.750 – 2.990 GHz