maria simanovskaia raman-excited spin coherences in nv centers in diamond
Post on 20-Dec-2015
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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!