Single-photon source

Last updated

A single-photon source is a light source that emits light as single particles or photons. Single-photon sources are distinct from coherent light sources (lasers) and thermal light sources such as incandescent light bulbs. The Heisenberg uncertainty principle dictates that a state with an exact number of photons of a single frequency cannot be created. However, Fock states (or number states) can be studied for a system where the electric field amplitude is distributed over a narrow bandwidth. In this context, a single-photon source gives rise to an effectively one-photon number state.

Contents

Photons from an ideal single-photon source exhibit quantum mechanical characteristics. These characteristics include photon antibunching, so that the time between two successive photons is never less than some minimum value. This behaviour can be experimentally demonstrated by using a beam splitter and single photon detectors, such as avalanche photodiodes, which monitor the output of the beam splitter. A detection from one detector is used to provide a ‘counter start’ signal, to a fast electronic timer, and the other, is used to provide a ‘counter stop’ signal. In the case of a stream of single photons to this measurement apparatus there will not be any coincidental detection events. By repeatedly measuring the times between ‘start’ and ‘stop’ signals, one can form a histogram of time delays between two consecutive photons. If a true single photon source is observed, the photons are timely separated and a clear notch around zero delay is visible.

History

Although the concept of a single photon was proposed by Planck as early as 1900, [1] a true single-photon source was not created in isolation until 1974. This was achieved by utilising a cascade transition within mercury atoms. [2] Individual atoms emit two photons at different frequencies in the cascade transition and by spectrally filtering the light the observation of one photon can be used to 'herald' the other. The observation of these single photons was characterised by its anticorrelation on the two output ports of a beamsplitter in a similar manner to the famous Hanbury Brown and Twiss experiment of 1956. [3]

Another single-photon source came in 1977 which used the fluorescence from an attenuated beam of sodium atoms. [4] A beam of sodium atoms was attenuated so that no more than one or two atoms contributed to the observed fluorescence radiation at any one time. In this way, only single emitters were producing light and the observed fluorescence showed the characteristic antibunching. The isolation of individual atoms continued with ion traps in the mid-1980s. A single ion could be held in a radio frequency Paul trap for an extended period of time (10 min) thus acting as a single emitter of multiple single photons as in the experiments of Diedrich and Walther. [5] At the same time the nonlinear process of parametric down conversion began to be utilised and from then until the present day it has become the workhorse of experiments requiring single photons.

Advances in microscopy led to the isolation of single molecules in the end of the 1980s. [6] Subsequently, single pentacene molecules were detected in p-terphenyl crystals. [7] The single molecules have begun to be utilised as single-photon sources. [8]

Within the 21st century defect centres in various solid state materials have emerged, [9] most notably diamond, silicon carbide [10] [11] and boron nitride. [12] the most studied defect is the nitrogen vacancy (NV) centers in diamond that was utilised as a source of single photons. [13] These sources along with molecules can use the strong confinement of light (mirrors, microresonators, optical fibres, waveguides, etc.) to enhance the emission of the NV centres. As well as NV centres and molecules, quantum dots (QDs), [14] quantum dots trapped in optical antenna, [15] functionalized carbon nanotubes, [16] [17] and two-dimensional materials [18] [19] [20] [21] [22] [23] [24] can also emit single photons and can be constructed from the same semiconductor materials as the light-confining structures. It is noted that the single photon sources at telecom wavelength of 1,550 nm are very important in fiber-optic communication and they are mostly indium arsenide QDs. [25] [26] However, by creating downconversion quantum interface from visible single photon sources, one still can create single photon at 1,550 nm with preserved antibunching. [27]

Exciting atoms and excitons to highly interacting Rydberg levels prevents more than one excitation over the so-called blockade volume. Hence Rydberg excitation in a small atomic ensembles [28] or crystals [29] could act as a single photon emitters.

Definition

In quantum theory, photons describe quantized electromagnetic radiation. Specifically, a photon is an elementary excitation of a normal mode of the electromagnetic field. Thus a single-photon state is the quantum state of a radiation mode that contains a single excitation.

Single radiation modes are labelled by, among other quantities, the frequency of the electromagnetic radiation that they describe. However, in quantum optics, single-photon states also refer to mathematical superpositions of single-frequency (monochromatic) radiation modes. [30] This definition is general enough to include photon wave-packets, i.e., states of radiation that are localized to some extent in space and time.

Single-photon sources generate single-photon states as described above. In other words, ideal single-photon sources generate radiation with a photon-number distribution that has a mean one and variance zero. [31]

Characteristics

An ideal-single photon source produces single-photon states with 100% probability and optical vacuum or multi-photon states with 0% probability. Desirable properties of real-world single-photon sources include efficiency, robustness, ease of implementation and on-demand nature, i.e., generating single-photons at arbitrarily chosen times. Single-photon sources including single emitters such as single atoms, ions and molecules, and including solid-state emitters such as quantum dots, color centers and carbon nanotubes are on-demand. [31] Currently, there are many active nanomaterials engineered into single quantum emitters where their spontaneous emission could be tuned by changing the local density of optical states in dielectric nanostructures. The dielectric nanostructures are usually designed within the heterostructures to enhance the light-matter interaction, and thus further improve the efficiency of these single photon sources. [32] [33] Another type of source comprises non-deterministic sources, i.e., not on demand, and these include examples such as weak lasers, atomic cascades and parametric down-conversion.

The single-photon nature of a source can be quantized using the second-order correlation function . Ideal single-photon sources show and good single-photon sources have small . The second-order correlation function can be measured using the Hanbury-Brown–Twiss effect.

Types

The generation of a single photon occurs when a source creates only one photon within its fluorescence lifetime after being optically or electrically excited. An ideal single-photon source has yet to be created. Given[ citation needed ] that the main applications for a high-quality single-photon source are quantum key distribution, quantum repeaters [34] [ dubious – discuss ] and quantum information science, the photons generated should also have a wavelength that would give low loss and attenuation when travelling through an optical fiber. Nowadays the most common sources of single photons[ citation needed ] are single molecules, Rydberg atoms, [35] [ dubious – discuss ] diamond colour centres and quantum dots, with the last being widely studied[ citation needed ]} with efforts from many research groups to realize quantum dots that fluoresce single photons at room temperature with photons in the low loss window of fiber-optic communication. For many purposes single photons need to be anti-bunched, and this can be verified.

Faint laser

One of the first and easiest sources was created by attenuating a conventional laser beam to reduce its intensity and thereby the mean photon number per pulse. [31] Since the photon statistics follow a Poisson distribution one can achieve sources with a well defined probability ratio for the emission of one versus two or more photons. For example, a mean value of μ = 0.1 leads to a probability of 90% for zero photons, 9% for one photon and 1% for more than one photon. [36]

Although such a source can be used for certain applications, it has a second-order intensity correlation function equal to one (no antibunching). For many applications however, antibunching is required, for instance in quantum cryptography.

Solid state single-photon emitters

Several different kinds of single-photon emitters have been demonstrated. These include devices based on color centers (point defects in crystals that fluoresce), certain two-dimensional materials, carbon nanotubes, and quantum dots. These types of sources are attractive in part because of the possibility of integrating the source with electronics on a single chip. [37]

Heralded single photons

Pairs of single photons can be generated in highly correlated states from using a single high-energy photon to create two lower-energy ones. One photon from the resulting pair may be detected to 'herald' the other (so its state is pretty well known prior to detection as long as the two photon state is separable, otherwise 'heralding' leaves heralded photon in a mixed state [38] ). The two photons need not generally be the same wavelength, but the total energy and resulting polarisation are defined by the generation process. One area of keen interest for such pairs of photons is quantum key distribution.

The heralded single-photon sources are also used to examine the fundamental physics laws in quantum mechanics. There are two commonly used types of heralded single-photon sources: spontaneous parametric down-conversion and spontaneous four-wave mixing. The first source has line-width around THz and the second one has line-width around MHz or narrower. The heralded single photon has been used to demonstrate photonics storage and loading to the optical cavity.

References

  1. ↑ Planck, M. (1900). "Über eine Verbesserung der Wienschen Spektralgleichung". Verhandlungen der Deutschen Physikalischen Gesellschaft . 2: 202–204.
  2. ↑ Clauser, John F. (1974). "Experimental distinction between the quantum and classical field-theoretic predictions for the photoelectric effect". Phys. Rev. D. 9 (4): 853–860. Bibcode:1974PhRvD...9..853C. doi:10.1103/physrevd.9.853. S2CID   118320287.
  3. ↑ Hanbury Brown, R.; Twiss, R. Q. (1956). "A test of a new type of stellar interferometer on sirius". Nature. 175 (4541): 1046–1048. Bibcode:1956Natur.178.1046H. doi:10.1038/1781046a0. S2CID   38235692.
  4. ↑ Kimble, H. J.; Dagenais, M.; Mandel, L. (1977). "Photon Antibunching in Resonance Fluorescence" (PDF). Phys. Rev. Lett. 39 (11): 691–695. Bibcode:1977PhRvL..39..691K. doi:10.1103/physrevlett.39.691.
  5. ↑ Diedrich, Frank; Walther, Herbert (1987). "Nonclassical Radiation of a Single Stored Ion". Phys. Rev. Lett. 58 (3): 203–206. Bibcode:1987PhRvL..58..203D. doi:10.1103/physrevlett.58.203. PMID   10034869.
  6. ↑ Moerner, W. E.; Kador, L. (22 May 1989). "Optical detection and spectroscopy of single molecules in a solid". Physical Review Letters. 62 (21): 2535–2538. Bibcode:1989PhRvL..62.2535M. doi: 10.1103/PhysRevLett.62.2535 . PMID   10040013.
  7. ↑ Orrit, M.; Bernard, J. (1990). "Single Pentacene Molecules Detected by Fluorescence Excitation in a p-Terphenyl Crystal". Phys. Rev. Lett. 65 (21): 2716–2719. Bibcode:1990PhRvL..65.2716O. doi:10.1103/physrevlett.65.2716. PMID   10042674.
  8. ↑ Basché, T.; Moerner, W.E.; Orrit, M.; Talon, H. (1992). "Photon antibunching in the fluorescence of a single dye molecule trapped in a solid". Phys. Rev. Lett. 69 (10): 1516–1519. Bibcode:1992PhRvL..69.1516B. doi:10.1103/PhysRevLett.69.1516. PMID   10046242. S2CID   44952356. Archived from the original on June 20, 2017.
  9. ↑ Aharonovich, Igor; Englund, Dirk; Toth, Milos (2016). "Solid-state single-photon emitters". Nature Photonics. 10 (10): 631–641. Bibcode:2016NaPho..10..631A. doi:10.1038/nphoton.2016.186. S2CID   43380771.
  10. ↑ Castelletto, S.; Johnson, B. C.; Ivády, V.; Stavrias, N.; Umeda, T.; Gali, A.; Ohshima, T. (February 2014). "A silicon carbide room-temperature single-photon source". Nature Materials. 13 (2): 151–156. Bibcode:2014NatMa..13..151C. doi:10.1038/nmat3806. ISSN   1476-1122. PMID   24240243. S2CID   37160386.
  11. ↑ Lohrmann, A.; Castelletto, S.; Klein, J. R.; Ohshima, T.; Bosi, M.; Negri, M.; Lau, D. W. M.; Gibson, B. C.; Prawer, S.; McCallum, J. C.; Johnson, B. C. (2016). "Activation and control of visible single defects in 4H-, 6H-, and 3C-SiC by oxidation". Applied Physics Letters. 108 (2): 021107. Bibcode:2016ApPhL.108b1107L. doi:10.1063/1.4939906.
  12. ↑ Tran, Toan Trong; Bray, Kerem; Ford, Michael J.; Toth, Milos; Aharonovich, Igor (2016). "Quantum emission from hexagonal boron nitride monolayers". Nature Nanotechnology. 11 (1): 37–41. arXiv: 1504.06521 . Bibcode:2016NatNa..11...37T. doi:10.1038/nnano.2015.242. PMID   26501751. S2CID   9840744.
  13. ↑ Kurtsiefer, Christian; Mayer, Sonja; Zarda, Patrick; Weinfurter, Harald (2000). "Stable Solid-State Source of Single Photons". Phys. Rev. Lett. 85 (2): 290–293. Bibcode:2000PhRvL..85..290K. doi:10.1103/physrevlett.85.290. PMID   10991265. S2CID   23862264.
  14. ↑ Michler, P.; Kiraz, A.; Becher, C.; Schoenfeld, W. V.; Petroff, P. M.; Zhang, Lidong; Imamoglu, A. (200). "A Quantum Dot Single-Photon Turnstile Device". Science. 290 (5500): 2282–2285. Bibcode:2000Sci...290.2282M. doi:10.1126/science.290.5500.2282. PMID   11125136.
  15. ↑ Jiang, Quanbo; Roy, Prithu; Claude, Jean-Benoît; Wenger, Jérôme (2021-08-25). "Single Photon Source from a Nanoantenna-Trapped Single Quantum Dot". Nano Letters. 21 (16): 7030–7036. arXiv: 2108.06508 . Bibcode:2021NanoL..21.7030J. doi:10.1021/acs.nanolett.1c02449. ISSN   1530-6984. PMID   34398613. S2CID   237091253.
  16. ↑ Htoon, Han; Doorn, Stephen K.; Baldwin, Jon K. S.; Hartmann, Nicolai F.; Ma, Xuedan (August 2015). "Room-temperature single-photon generation from solitary dopants of carbon nanotubes". Nature Nanotechnology. 10 (8): 671–675. Bibcode:2015NatNa..10..671M. doi:10.1038/nnano.2015.136. ISSN   1748-3395. PMID   26167766.
  17. ↑ He, Xiaowei; Hartmann, Nicolai F.; Ma, Xuedan; Kim, Younghee; Ihly, Rachelle; Blackburn, Jeffrey L.; Gao, Weilu; Kono, Junichiro; Yomogida, Yohei (September 2017). "Tunable room-temperature single-photon emission at telecom wavelengths from sp3 defects in carbon nanotubes". Nature Photonics. 11 (9): 577–582. doi:10.1038/nphoton.2017.119. ISSN   1749-4885. OSTI   1379462. S2CID   36377957.
  18. ↑ Tonndorf, Philipp; Schmidt, Robert; Schneider, Robert; Kern, Johannes; Buscema, Michele; Steele, Gary A.; Castellanos-Gomez, Andres; van der Zant, Herre S. J.; Michaelis de Vasconcellos, Steffen (2015-04-20). "Single-photon emission from localized excitons in an atomically thin semiconductor". Optica. 2 (4): 347. Bibcode:2015Optic...2..347T. doi: 10.1364/OPTICA.2.000347 . ISSN   2334-2536.
  19. ↑ Chakraborty, Chitraleema; Kinnischtzke, Laura; Goodfellow, Kenneth M.; Beams, Ryan; Vamivakas, A. Nick (June 2015). "Voltage-controlled quantum light from an atomically thin semiconductor". Nature Nanotechnology. 10 (6): 507–511. Bibcode:2015NatNa..10..507C. doi:10.1038/nnano.2015.79. ISSN   1748-3387. PMID   25938569.
  20. ↑ Palacios-Berraquero, Carmen; Barbone, Matteo; Kara, Dhiren M.; Chen, Xiaolong; Goykhman, Ilya; Yoon, Duhee; Ott, Anna K.; Beitner, Jan; Watanabe, Kenji (December 2016). "Atomically thin quantum light-emitting diodes". Nature Communications. 7 (1): 12978. arXiv: 1603.08795 . Bibcode:2016NatCo...712978P. doi:10.1038/ncomms12978. ISSN   2041-1723. PMC   5052681 . PMID   27667022.
  21. ↑ Palacios-Berraquero, Carmen; Kara, Dhiren M.; Montblanch, Alejandro R.-P.; Barbone, Matteo; Latawiec, Pawel; Yoon, Duhee; Ott, Anna K.; Loncar, Marko; Ferrari, Andrea C. (August 2017). "Large-scale quantum-emitter arrays in atomically thin semiconductors". Nature Communications. 8 (1): 15093. arXiv: 1609.04244 . Bibcode:2017NatCo...815093P. doi:10.1038/ncomms15093. ISSN   2041-1723. PMC   5458119 . PMID   28530249.
  22. ↑ Branny, Artur; Kumar, Santosh; Proux, Raphaël; Gerardot, Brian D (August 2017). "Deterministic strain-induced arrays of quantum emitters in a two-dimensional semiconductor". Nature Communications. 8 (1): 15053. arXiv: 1610.01406 . Bibcode:2017NatCo...815053B. doi:10.1038/ncomms15053. ISSN   2041-1723. PMC   5458118 . PMID   28530219.
  23. ↑ Wu, Wei; Dass, Chandriker K.; Hendrickson, Joshua R.; Montaño, Raul D.; Fischer, Robert E.; Zhang, Xiaotian; Choudhury, Tanushree H.; Redwing, Joan M.; Wang, Yongqiang (2019-05-27). "Locally defined quantum emission from epitaxial few-layer tungsten diselenide". Applied Physics Letters. 114 (21): 213102. Bibcode:2019ApPhL.114u3102W. doi: 10.1063/1.5091779 . hdl: 10150/634575 . ISSN   0003-6951.
  24. ↑ He, Yu-Ming; Clark, Genevieve; Schaibley, John R.; He, Yu; Chen, Ming-Cheng; Wei, Yu-Jia; Ding, Xing; Zhang, Qiang; Yao, Wang (June 2015). "Single quantum emitters in monolayer semiconductors". Nature Nanotechnology. 10 (6): 497–502. arXiv: 1411.2449 . Bibcode:2015NatNa..10..497H. doi:10.1038/nnano.2015.75. ISSN   1748-3387. PMID   25938571. S2CID   205454184.
  25. ↑ Birowosuto, M. D.; Sumikura, H.; Matsuo, S.; Taniyama, H.; Veldhoven, P.J.; Notzel, R.; Notomi, M. (2012). "Fast Purcell-enhanced single photon source in 1,550-nm telecom band from a resonant quantum dot-cavity coupling". Sci. Rep. 2: 321. arXiv: 1203.6171 . Bibcode:2012NatSR...2..321B. doi:10.1038/srep00321. PMC   3307054 . PMID   22432053.
  26. ↑ Muller, T.; Skiba-Szymanska, J.; Krysa, A.B.; Huwer, J.; Felle, M.; Anderson, M.; Stevenson, R.M.; Heffernan, J.; Ritchie, D.A.; Shields, A.J. (2018). "A quantum light-emitting diode for the standard telecom window around 1,550 nm". Nat. Commun. 9 (1): 862. arXiv: 1710.03639 . Bibcode:2018NatCo...9..862M. doi:10.1038/s41467-018-03251-7. PMC   5830408 . PMID   29491362.
  27. ↑ Pelc, J.S.; Yu, L.; De Greve, K.; McMahon, P.L.; Natarajan, C.M.; Esfandyarpour, V.; Maier, S.; Schneider, C.; Kamp, M.; Shields, A.J.; Höfling, A.J.; Hadfield, R.; Forschel, A.; Yamamoto, Y. (2012). "Downconversion quantum interface for a single quantum dot spin and 1550-nm single-photon channel". Opt. Express. 20 (25): 27510–9. arXiv: 1209.6404 . Bibcode:2012OExpr..2027510P. doi:10.1364/OE.20.027510. PMID   23262701. S2CID   847645.
  28. ↑ Dudin, Y. O.; Kuzmich, A. (2012-05-18). "Strongly Interacting Rydberg Excitations of a Cold Atomic Gas". Science. 336 (6083): 887–889. Bibcode:2012Sci...336..887D. doi: 10.1126/science.1217901 . ISSN   0036-8075. PMID   22517325. S2CID   206539415.
  29. ↑ Khazali, Mohammadsadegh; Heshami, Khabat; Simon, Christoph (2017-10-23). "Single-photon source based on Rydberg exciton blockade". Journal of Physics B: Atomic, Molecular and Optical Physics. 50 (21): 215301. arXiv: 1702.01213 . Bibcode:2017JPhB...50u5301K. doi:10.1088/1361-6455/aa8d7c. ISSN   0953-4075. S2CID   118910311.
  30. ↑ Scully, Marlan O. (1997). Quantum optics. Zubairy, Muhammad Suhail, 1952-. Cambridge: Cambridge University Press. ISBN   9780521435956. OCLC   817937365.
  31. 1 2 3 Eisaman, M. D.; Fan, J.; Migdall, A.; Polyakov, S. V. (2011-07-01). "Invited Review Article: Single-photon sources and detectors". Review of Scientific Instruments. 82 (7): 071101–071101–25. Bibcode:2011RScI...82g1101E. doi: 10.1063/1.3610677 . ISSN   0034-6748. PMID   21806165.
  32. ↑ Birowosuto, M.; et al. (2014). "Movable high-Q nanoresonators realized by semiconductor nanowires on a Si photonic crystal platform". Nature Materials. 13 (3): 279–285. arXiv: 1403.4237 . Bibcode:2014NatMa..13..279B. doi:10.1038/nmat3873. PMID   24553654. S2CID   21333714.
  33. ↑ Diguna, L., Birowosuto, M; et al. (2018). "Light–matter interaction of single quantum emitters with dielectric nanostructures". Photonics. 5 (2): 14. Bibcode:2018Photo...5...14D. doi: 10.3390/photonics5020014 . hdl: 10220/45525 .{{cite journal}}: CS1 maint: multiple names: authors list (link)
  34. ↑ Meter, R.V.; Touch, J. (2013). "Designing quantum repeater networks". IEEE Communications Magazine. 51 (8): 64–71. doi:10.1109/mcom.2013.6576340. S2CID   27978069.
  35. ↑ Dudin, Y. O.; Kuzmich, A. (2012-04-19). "Strongly Interacting Rydberg Excitations of a Cold Atomic Gas". Science. 336 (6083): 887–889. Bibcode:2012Sci...336..887D. doi: 10.1126/science.1217901 . ISSN   0036-8075. PMID   22517325. S2CID   206539415.
  36. ↑ Al-Kathiri, S.; Al-Khateeb, W.; Hafizulfika, M.; Wahiddin, M. R.; Saharudin, S. (May 2008). "Characterization of mean photon number for key distribution system using faint laser". 2008 International Conference on Computer and Communication Engineering. pp. 1237–1242. doi:10.1109/ICCCE.2008.4580803. ISBN   978-1-4244-1691-2. S2CID   18300454.
  37. ↑ Aharonovich, Igor; Englund, Dirk; Toth, Milos (2016). "Solid-state single-photon emitters". Nature Photonics. 10 (10): 631–641. doi:10.1038/nphoton.2016.186. ISSN   1749-4885.
  38. ↑ Mosley, Peter J.; Lundeen, Jeff S.; Smith, Brian J.; Wasylczyk, Piotr; U’Ren, Alfred B.; Silberhorn, Christine; Walmsley, Ian A. (2008-04-03). "Heralded Generation of Ultrafast Single Photons in Pure Quantum States". Physical Review Letters. 100 (13): 133601. arXiv: 0711.1054 . Bibcode:2008PhRvL.100m3601M. doi:10.1103/PhysRevLett.100.133601. ISSN   0031-9007. PMID   18517952. S2CID   21174398.

Bibliography

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.