Photoinduced Fields L C Basset F J Heremans C G Yale B B Buckley and A Awschalom PRL 107 266403 2011 Motivation NV centers are sensitive to their local environment gt sample ID: 602303
Download Presentation The PPT/PDF document "Electrical Tuning of Single Nitrogen-Vac..." is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
Electrical Tuning of Single Nitrogen-Vacancy Center Optical Transitions Enhanced by Photoinduced Fields
L. C. Basset, F.
J
.
Heremans
, C. G. Yale, B. B. Buckley, and A.
Awschalom
PRL 107, 266403 (2011)Slide2
Motivation
NV centers are sensitive to their local environment -> sample
inhomogeneities
result in distribution of ZPL lines (strain, electrostatic charges)
Successful entanglement requires identical photons
How to tune emission?
Dc Stark effect – electric fields perturb both the ground and excited state orbitals
Compensate intrinsic local strain and electrostatic fields of NV centers with an external fieldSlide3
NV center in diamond
C
3v
symmetry
ZPL transitions around 637.2 nm (1.946eV)
Resonant
transitions
(637 nm)
Excite with
532 nm
Detection
Intersystem
c
rossing (dark)
3
A
2
3
E
x
,
3
E
y
1
A
1
1
E
Level splitting due to
s
train fields
3
E
x
3
E
y
m
S
=+1
m
S
=0
m
S
=-1
e
-
NV
-
center
i
n diamond
latticeSlide4
Earlier work on Stark effect in single NV centers
Stark Shift Control of Single Optical Centers in Diamond
Ph.
Tamarat
et al., PRL 97, 083002 (2006)
Mo/Ag electrodes, spacing=50 mm
400nm SiO2 overcoat
Stark shift given by
w
ith F the local electric field
Linear dependency for degenerate excited states
Quadratic dependency for non-degenerate states (strain, orientation of NV with respect to field)
Density-functional calculations confirm orientation-dependent breakage of electronic symmetry in electric field
Slide5
Sample prep and measurement setup
CVD diamond, <5ppb nitrogen (Element6)
Electron irradiated (2 MeV, 1.2E14cm
-2
)
Annealed at 800C
Electrodes are either Ti/
Pt
/ Au or ITO
Measurements at 20K
No magnetic field
532 nm repump
to maintain spin-polarized population in /Sz>Record PLE into red-shifted
phonen sidebandBias pulsed at 1 kHzSlide6
Hamiltonian
Symmetrized field strengths
Transition energy eigenvalues
Local field can cancel transverse comp.
of intrinsic strain.Slide7
Lateral tuning
Kink at 0 V due to asymmetry in electric field, photoionization of charge traps (N at ~1.7eV
below conduction band edge of diamond) -> long-lived non-equilibrium charges
Crossing at 7 V shows restoration of C
3v
symmetry
[
110]
[-110]
[001]Slide8
Stark shift response for vertical tuning
Transparent ITO top gate
Stark shift due to tuning with top gate amplified compared to lateral tuning
Positive charges in illuminated volume below NV are assumed to rectify Z component of E-field
Photoexcitation
of N donors results in out-of-plane field
F=
F=
β
Vv
+
β
|V|
ξSlide9
Comparison of measurement outcome and model predictions
Slide10
Tuning diagram – 3D control of local field vector