maria simanovskaia raman-excited spin coherences in nv centers in diamond

Maria Simanovskaia

Raman-excited spin coherences in NV centers in

diamond

ExperimentsNon-degenerate four wave mixingElectromagnetically induced transparency

Non-degenerate four wave mixingNV diamond sample has ~30 ppm color centers, has

peak optical density of ~0.6 for 1 W/cm2 probe intensity at 15 K

Used one dye laser, with acousto-optic frequency shiftersDownshifted R1, R2, P from original frequency by

400, 280, and 420 MHz, respectivelyIntensities of R1, R2, P and repump beam were

1.2, 1.6, 5.6, 10 W/cm2

120 MHz

20 MHz

DP

R1

R2

S = −1

S = 0

Fine structure

• Sublevel splitting due to external magnetic field

S = −1

S = +1

S = ±1

0 G 1050 GB-field

S = 0 2.88 GHz

120 MHz

120 MHz

20 MHz

DP

R1

R2

S = −1

S = 0

Non-degenerate four wave mixing

3.5° intersection angleTo complete equivalence: kD = kR2 − kR1 + kP

514.5 nm argon laser used as a repumpProtect against spectral hole burning

Helmholtz coilsLaser beams: linearly polarized, focused by 150-mm

focal length lens15 K maintained by Janis helium-flow cryostat

Dye laserDetector

Optics

Results: NDFWMNarrow linewidth is taken as

evidence of Raman processHomogeneous width of optical transition (~50 MHz)Inhomogeneous width of spin transition (5 MHz)

Recall: for NDFWM, intensities of R1, R2, P and repump beam were 1.2, 1.6, 5.6, 10 W/cm2

Saturation intensities are 36 W/cm2 and 56 W/cm2 for optical transitions resonant with R1 and R2, respectively

Electromagnetically induced transparency

Lambda EIT schemeUsed R2, R1 and

repump beams 120 MHz

Coupling: R1,280 W/cm2

Probe: R2, 1 W/cm2

S = −1

S = 0

R2, no diamond

Freq.

% T

rans

mis

sion

120 MHz

R2, with diamond

Freq.

% T

rans

mis

sion

120 MHz

R2, with diamond and R1

Freq.%

Tra

nsm

issi

on120 MHz

difference difference difference

Results: EITMax value of transparency is 17% of

background absorption70% of what is possible (random orientation of NV

center in diamond)EIT linewidth is substantially

smaller than laser jitter (~100 MHz) and the optical homogeneous linewidth

Thank you!