1. Quantum photonics: nitrogen-vacancy
centers in diamond
by Tejasvi Parupudi, Amr Emadeldin, Rajtarun Madangopal, and Mikhail Shalaginov

2. Stuck in the Internet highway "traffic" jam
Phil Kerpen
"Information super
traffic jams",
Forbes 2007

3. Promising ways of developing IT
• Optical computing
• Quantum computing
• Quantum cryptography
• Spintronics
• DNA computing
• Artificial intelligence

4. Opportunities
Quantum entanglement and
teleportation of well secured information,
much faster mechanisms of processing information
Shor’s algorithm

5. Macroscopic "single-photon" sources
Lounis and Orrit, Rep. Prog. Phys. 68 (2005) 1129–1179

6. Trapped ions:
Cs, Rb
Color centers in diamond Quantum dots
Microscopic single-photon sources

7. Nitrogen-vacancy color center in diamond as
one of the best candidates to be used in
future quantum technologies as a single-
photon source

8. Nitrogen Vacancy Center
Aharonovich et al., Nature Photonics, 2011

9. NANODIAMONDS
•Detonation process
•Microwave-assisted CVD
•Crushing of synthetic/natural
diamonds
DIAMOND WAFERS
HPHT/ High-plasma density CVD -
single crystal diamond wafers
fabrication
Aharonovich et al., Nature Photonics, 2011
C. Bradac, et al., Nature Nanotechnology, 5, 345-349 (2010)

10. •Nitrogen – most common
impurity;
•Irradiation with electron/He2+ –
creation of vacancies;
•Annealing – diffusion of
vacancies and subsequent
formation of NVs
Robledo et al., PRL 105, 177403, 2010

11. Electronic level structure of NV center
Pham et al. New Journal of Physics (2011) vol. 13 pp. 045021

12. Spectrum of NV center
S. Schietinger, Nano Lett, 8,11, 2008

13. 2nd order correlation function g(2)(τ)
http://spie.org/x40194.xml?ArticleID=x40194

14. Properties of NV Centers
Stable against photobleaching
Kurtsiefer et al., PRL, 85, 2, 2000
Long spin coherence times > 1.8 ms
Stanwix et al., arXiv, Cond. Matter, 2011
Room temperature single spin read out
Stanwix et al., arXiv, Cond. Matter, 2011
Photoluminiscence at room temperature
Kennedy et al., APL, 83, 20, 2003

15. Promising applications of
NV-centers in quantum
computing

16. Quantum computation
• ıc›=a ıo› + b ı1›
• Coherence
• Entanglement
• Secure communications
• Shor’s algorithm
• Grover’s algorithm (entanglement to process multi-states in
parallel)

17. Using nanodiamond NV centers for
quantum processing
Single photon sources could be coupled to
cavities (CQED)
Two approaches:
• NV centers contain qubits coupled and entangled with
photons
• Photons are qubits entangled by non-linearities in NV centers
(like EIT)

18. Repeat until success
Lim et al, “Repeat until success quantum
computing”, U Cmabridge,2008
Bell measurement,
interferometry ,
Grentree et al , “Diamond integrated
quantum photonics”

19. Brokered graph-state quantum
computation

20. Weak non-linearities
• Single-photon generation
• Entanglement parity operation
• Non-demolition measurement
Munro et al, “weak non-linearities: A new route
to optical quantum computation ” 2005

21. Electromagnetic Induced
Transparency
• Equivalent to Kerr effect, EIT is the source of non-linearity
• Applicable to diamond case
Beasoleile et al, “Application EIT to Quantum Information Processing ”, 2004

22. Coupling photons to surrounding
• Cavity QED
• Photonic module

23. Diamond for quantum computing

24. Other promising applications of
NV-centers in diamond

25. Ampem-Lassen et al. Opt Express (2009) vol. 17 (14) pp. 11287-93
Fluorescence emission from NV center

26. NanoDiamond vs. Other ‘Fluorophores’
Say et al. Biophysical Reviews (Oct 2011)

27. Fluorescent NanoDiamonds for Imaging
Chang et al, Nature Nanotechnology (2008) vol. 3 (5) pp. 284-288
Imaging of both fast (ms) and slow (h) events in cells, tissues & even small animals.
3D tracking of a single 35-nm FND in a live HeLa cell 3D TPE image of cell and internalized FNDs
OPE and TPE confocal fluorescence images of same cell Epifluorescence & 3D reconstruction

28. Hell et al., Current opinion in Neurobiology (2004) vol. 14 (5) pp. 599-609
Stimulated Emission Depletion Microscopy

29. Stimulated Emission Depletion Microscopy
Hein et al. Proceedings of the National Academy of Sciences (2008) vol. 105 (38) pp. 14271

30. Aharonovich et al., Nature Photonics (2011) vol. 5 pp. 397-405
NV Color Centers & STED
• Conventional fluorescent markers
have limited photostability & get
photobleached.
• QDs are photostable but not
compatible with STED
• NV centers are photostable – limited
photobleaching at high excitation
intensities.

31. Pham et al. New Journal of Physics (2011) vol. 13 pp. 045021
NV Center’s electronic structure allows:
• Optical initialization and detection of the spin state
• Long room temperature spin coherence times
Nanoscale Magnetic Sensing & Magnetic Field Imaging

32. Pham et al. , New Journal of Physics (2011) vol. 13 pp. 045021
Magnetic Field Imaging

33. Conclusions
Nitrogen-vacancy (NV) center – promising microscopic single-photon source.
Important properties:
????
Other promising applications:
•photostable,
•operates at room temperature,
•broadband emission spectrum,
•long spin coherence time,
•non-toxic.
•biolabeling,
•fluorescent imaging (with STED),
•magnetic sensing and magnetic field imaging.

34. Bonus Movie

36. Appendix

37. Quantum photonics: nitrogen-
vacancy centers in diamond
by Tejasvi Parupudi, Amr Emadeldin,
Rajtarun Madangopal, and Mikhail
Shalaginov