Silicon carbide color centers

There are mainly three methods for fabricating silicon carbide color centers.{{Cite journal |last1=Huang |first1=Qieyu |last2=Huang |first2=Kun |last3=Cheng |first3=Lin |last4=Qu |first4=Shuai |last5=Ran |first5=Guihao |last6=Mao |first6=Xiaobiao |date=2022-11-21 |title=Fabrication and Detection of Silicon Carbide Color Centers Based on Nanosecond Laser Technology |url=https://link.springer.com/10.1007/s10946-022-10098-3 |journal=Journal of Russian Laser Research |language=en |volume=43 |issue=6 |pages=708–714 |doi=10.1007/s10946-022-10098-3 |s2cid=253784844 |issn=1071-2836}} The three methods are electronic irradiation, ion injection, and femtosecond laser writing.

This technique works by exposing the material to an electron beam that is highly ionizing. This knocks off electrons in the material itself, which generates color centers (or defects).{{Cite conference|last1=Idris |first1=Sarada |last2=Ghazali |first2=Zulkafli |last3=Hashim |first3=Siti A'iasah |last4=Ahmad |first4=Shamshad |last5=Jusoh |first5=Mohd Suhaimi |conference=American Institute of Physics |id=1482 |date=2012 |title=Electron beam irradiation of gemstone for color enhancement |url=http://aip.scitation.org/doi/abs/10.1063/1.4757464 |location=Kuala Lumpur, Malaysia |pages=197–199 |doi=10.1063/1.4757464}} This process however, requires a large amount of energy, having 9MeV normally being the lower limit of energy in most materials.

Ion injection is normally used to dope semiconductors, but it can also be used to create color centers. An ion is first accelerated to a certain energy, normally in the MeV range. This ion is then accelerated into the material, which then implants the ion into the material, changing the material composition, which can create a color center.{{Cite journal |last1=Lagomarsino |first1=S. |last2=Flatae |first2=A. M. |last3=Kambalathmana |first3=H. |last4=Sledz |first4=F. |last5=Hunold |first5=L. |last6=Soltani |first6=N. |last7=Reuschel |first7=P. |last8=Sciortino |first8=S. |last9=Gelli |first9=N. |last10=Massi |first10=M. |last11=Czelusniak |first11=C. |last12=Giuntini |first12=L. |last13=Agio |first13=M. |date=2021-01-14 |title=Creation of Silicon-Vacancy Color Centers in Diamond by Ion Implantation |journal=Frontiers in Physics |volume=8 |pages=601362 |doi=10.3389/fphy.2020.601362 |bibcode=2021FrP.....8..626L |issn=2296-424X|doi-access=free |hdl=2158/1244714 |hdl-access=free }}

Utilizing a nonlinear laser writing process, along with the appropriate aberration correction, defects can be generated at any depth in the crystal. This process preserves spin and optical coherence properties.{{Cite journal |last1=Chen |first1=Yu-Chen |last2=Griffiths |first2=Benjamin |last3=Weng |first3=Laiyi |last4=Nicley |first4=Shannon S. |last5=Ishmael |first5=Shazeaa N. |last6=Lekhai |first6=Yashna |last7=Johnson |first7=Sam |last8=Stephen |first8=Colin J. |last9=Green |first9=Ben L. |last10=Morley |first10=Gavin W. |last11=Newton |first11=Mark E. |last12=Booth |first12=Martin J. |last13=Salter |first13=Patrick S. |last14=Smith |first14=Jason M. |date=2019-05-20 |title=Laser writing of individual nitrogen-vacancy defects in diamond with near-unity yield |url=https://opg.optica.org/abstract.cfm?URI=optica-6-5-662 |journal=Optica |language=en |volume=6 |issue=5 |pages=662 |doi=10.1364/OPTICA.6.000662 |arxiv=1807.04028 |bibcode=2019Optic...6..662C |s2cid=119475807 |issn=2334-2536}}{{Cite journal |last1=Chen |first1=Yu-Chen |last2=Salter |first2=Patrick S. |last3=Niethammer |first3=Matthias |last4=Widmann |first4=Matthias |last5=Kaiser |first5=Florian |last6=Nagy |first6=Roland |last7=Morioka |first7=Naoya |last8=Babin |first8=Charles |last9=Erlekampf |first9=Jürgen |last10=Berwian |first10=Patrick |last11=Booth |first11=Martin J. |last12=Wrachtrup |first12=Jörg |date=2019-04-10 |title=Laser Writing of Scalable Single Color Centers in Silicon Carbide |url=https://pubs.acs.org/doi/10.1021/acs.nanolett.8b05070 |journal=Nano Letters |language=en |volume=19 |issue=4 |pages=2377–2383 |doi=10.1021/acs.nanolett.8b05070 |pmid=30882227 |bibcode=2019NanoL..19.2377C |s2cid=81980022 |issn=1530-6984}} The way it works is from multiphoton ionization from the femtosecond laser process. This method of fabricating defects does not only work for silicon carbide, but can also work for other materials.{{Cite journal |last1=Courrol |first1=Lilia Coronato |last2=Samad |first2=Ricardo Elgul |last3=Gomez |first3=Laércio |last4=Ranieri |first4=Izilda Márcia |last5=Baldochi |first5=Sonia Licia |last6=Zanardi de Freitas |first6=Anderson |last7=Vieira |first7=Nilson Dias |date=2004-01-09 |title=Color center production by femtosecond pulse laser irradiation in LiF crystals |url=https://opg.optica.org/oe/abstract.cfm?uri=oe-12-2-288 |journal=Optics Express |language=en |volume=12 |issue=2 |pages=288–293 |doi=10.1364/OPEX.12.000288 |pmid=19471536 |bibcode=2004OExpr..12..288C |issn=1094-4087|doi-access=free }}

Other types of fabrication for defects are neutron irradiation, proton irradiation, and focused Si beams.{{Cite journal |last1=Castelletto |first1=Stefania |last2=Boretti |first2=Alberto |date=2020-04-01 |title=Silicon carbide color centers for quantum applications |journal=Journal of Physics: Photonics |volume=2 |issue=2 |pages=022001 |doi=10.1088/2515-7647/ab77a2 |bibcode=2020JPhP....2b2001C |s2cid=214158020 |issn=2515-7647|doi-access=free }}

Currently{{When|date=December 2022}}, new methods of fabrication are also being experimented with to try and reduce the energy used, or the complication of the process. One of the new methods is a new method of utilizing a laser writing method with a nanosecond laser.

There are multiple types of defects in silicon carbide, some of which are listed below:{{clarify|What do these letters mean?|date=December 2022}}

• V_si^(-) (TV1-TV3)
• V_siV_C⁽⁰⁾
• DV⁽⁰⁾
• Ky5
• CAV (Carbon anti-site-vacancy pair)
• SiC(D₁)
• N_CV_Si^(-)

Transition metal color centers:

• TI⁽⁰⁾
• Cr³⁺
• V^(-), V⁽⁰⁾
• Mo⁽⁰⁾
• Er³⁺

Studies have been done on TV1 as a qubit, which provided a better spin-photon interface than TV2.{{Cite journal |last1=Nagy |first1=Roland |last2=Niethammer |first2=Matthias |last3=Widmann |first3=Matthias |last4=Chen |first4=Yu-Chen |last5=Udvarhelyi |first5=Péter |last6=Bonato |first6=Cristian |last7=Hassan |first7=Jawad Ul |last8=Karhu |first8=Robin |last9=Ivanov |first9=Ivan G. |last10=Son |first10=Nguyen Tien |last11=Maze |first11=Jeronimo R. |last12=Ohshima |first12=Takeshi |last13=Soykal |first13=Öney O. |last14=Gali |first14=Ádám |last15=Lee |first15=Sang-Yun |date=2019-04-26 |title=High-fidelity spin and optical control of single silicon-vacancy centres in silicon carbide |journal=Nature Communications |language=en |volume=10 |issue=1 |pages=1954 |doi=10.1038/s41467-019-09873-9 |issn=2041-1723 |pmc=6486615 |pmid=31028260|arxiv=1810.10296 |bibcode=2019NatCo..10.1954N }}{{Cite journal |last1=Nagy |first1=Roland |last2=Widmann |first2=Matthias |last3=Niethammer |first3=Matthias |last4=Dasari |first4=Durga B. R. |last5=Gerhardt |first5=Ilja |last6=Soykal |first6=Öney O. |last7=Radulaski |first7=Marina |last8=Ohshima |first8=Takeshi |last9=Vučković |first9=Jelena |last10=Son |first10=Nguyen Tien |last11=Ivanov |first11=Ivan G. |last12=Economou |first12=Sophia E. |author12-link=Sophia Economou|last13=Bonato |first13=Cristian |last14=Lee |first14=Sang-Yun |last15=Wrachtrup |first15=Jörg |date=2018-03-23 |title=Quantum Properties of Dichroic Silicon Vacancies in Silicon Carbide |url=https://link.aps.org/doi/10.1103/PhysRevApplied.9.034022 |journal=Physical Review Applied |language=en |volume=9 |issue=3 |pages=034022 |doi=10.1103/PhysRevApplied.9.034022 |arxiv=1707.02715 |bibcode=2018PhRvP...9c4022N |s2cid=53484272 |issn=2331-7019}} Recently however, the role of V_si^(-) as a qubit has been full identified.{{Cite journal |last1=Ivády |first1=Viktor |last2=Davidsson |first2=Joel |last3=Son |first3=Nguyen Tien |last4=Ohshima |first4=Takeshi |last5=Abrikosov |first5=Igor A. |last6=Gali |first6=Adam |date=2017-10-27 |title=Identification of Si-vacancy related room-temperature qubits in 4 H silicon carbide |url=https://link.aps.org/doi/10.1103/PhysRevB.96.161114 |journal=Physical Review B |language=en |volume=96 |issue=16 |pages=161114 |doi=10.1103/PhysRevB.96.161114 |arxiv=1708.06259 |bibcode=2017PhRvB..96p1114I |s2cid=6668026 |issn=2469-9950}}

Recently{{When|date=December 2022}}, these color centers in silicon carbide have shown promise in becoming one of the best single-photon emitters for non-classical light sources.{{Cite journal |last1=Khramtsov |first1=Igor A. |last2=Fedyanin |first2=Dmitry Yu. |date=2021-03-06 |title=Single-Photon Sources Based on Novel Color Centers in Silicon Carbide P–I–N Diodes: Combining Theory and Experiment |journal=Nano-Micro Letters |language=en |volume=13 |issue=1 |pages=83 |doi=10.1007/s40820-021-00600-y |issn=2311-6706 |pmc=8006472 |pmid=34138328 |bibcode=2021NML....13...83K }} Traditionally, attenuated lasers have been the substitute for single-photon sources. This works for quantum cryptography, but they are a partial substitute, and in the end this was not a substitute for single-photon sources as they do not produce single photons. Normally, there are two main methods of generating single photons: spontaneous parametric down-conversion and epitaxial quantum dots.{{citation needed|date=December 2022}}

In spontaneous parametric down-conversion, single photons can be produced up to a rate of 10⁶ photons per second.{{Cite journal |last1=Montaut |first1=Nicola |last2=Sansoni |first2=Linda |last3=Meyer-Scott |first3=Evan |last4=Ricken |first4=Raimund |last5=Quiring |first5=Viktor |last6=Herrmann |first6=Harald |last7=Silberhorn |first7=Christine |date=2017-08-22 |title=High-Efficiency Plug-and-Play Source of Heralded Single Photons |url=https://link.aps.org/doi/10.1103/PhysRevApplied.8.024021 |journal=Physical Review Applied |language=en |volume=8 |issue=2 |pages=024021 |doi=10.1103/PhysRevApplied.8.024021 |arxiv=1701.04229 |bibcode=2017PhRvP...8b4021M |s2cid=690463 |issn=2331-7019}}{{Cite journal |last1=Guo |first1=Xiang |last2=Zou |first2=Chang-ling |last3=Schuck |first3=Carsten |last4=Jung |first4=Hojoong |last5=Cheng |first5=Risheng |last6=Tang |first6=Hong X |date=2017-11-07 |title=Parametric down-conversion photon-pair source on a nanophotonic chip |journal=Light: Science & Applications |language=en |volume=6 |issue=5 |pages=e16249 |doi=10.1038/lsa.2016.249 |issn=2047-7538 |pmc=6062195 |pmid=30167250|arxiv=1603.03726 |bibcode=2016LSA.....6E6249G }}{{Cite journal |last1=Caspani |first1=Lucia |last2=Xiong |first2=Chunle |last3=Eggleton |first3=Benjamin J |last4=Bajoni |first4=Daniele |last5=Liscidini |first5=Marco |last6=Galli |first6=Matteo |last7=Morandotti |first7=Roberto |last8=Moss |first8=David J |date=2017-06-06 |title=Integrated sources of photon quantum states based on nonlinear optics |journal=Light: Science & Applications |language=en |volume=6 |issue=11 |pages=e17100 |doi=10.1038/lsa.2017.100 |issn=2047-7538 |pmc=6062040 |pmid=30167217|bibcode=2017LSA.....6E7100C }} The drawback to this approach is that there is no way to generate single photons on demand. This makes this type of generation hard to use practically.{{citation needed|date=December 2022}}

Epitaxial quantum dots are shown to generate single photons exceptionally when put under electrical pumping. This however works under very low temperatures, which also makes these applications harder to do practically in experiments.{{Cite journal |last1=Buckley |first1=Sonia |last2=Rivoire |first2=Kelley |last3=Vučković |first3=Jelena |date=2012-12-01 |title=Engineered quantum dot single-photon sources |url=https://iopscience.iop.org/article/10.1088/0034-4885/75/12/126503 |journal=Reports on Progress in Physics |volume=75 |issue=12 |pages=126503 |doi=10.1088/0034-4885/75/12/126503 |pmid=23144123 |arxiv=1210.1234 |bibcode=2012RPPh...75l6503B |s2cid=14389032 |issn=0034-4885}}{{Cite journal |last1=Senellart |first1=Pascale |last2=Solomon |first2=Glenn |last3=White |first3=Andrew |date=2017-11-07 |title=High-performance semiconductor quantum-dot single-photon sources |url=http://www.nature.com/articles/nnano.2017.218 |journal=Nature Nanotechnology |language=en |volume=12 |issue=11 |pages=1026–1039 |doi=10.1038/nnano.2017.218 |pmid=29109549 |bibcode=2017NatNa..12.1026S |issn=1748-3387}}{{Cite journal |last1=Deshpande |first1=Saniya |last2=Frost |first2=Thomas |last3=Hazari |first3=Arnab |last4=Bhattacharya |first4=Pallab |date=2014-10-06 |title=Electrically pumped single-photon emission at room temperature from a single InGaN/GaN quantum dot |url=http://aip.scitation.org/doi/10.1063/1.4897640 |journal=Applied Physics Letters |language=en |volume=105 |issue=14 |pages=141109 |doi=10.1063/1.4897640 |bibcode=2014ApPhL.105n1109D |issn=0003-6951}}

Color centers in silicon carbide, diamonds, and other related materials would be more practical that the two other traditional approaches due to the higher temperature that they can operate at when under optical and electrical pumping.

Silicon carbide is currently being used in the semiconductor industry already, due to the fact that it belongs to a family of materials called complementary metal–oxide–semiconductor compatible materials, as well as its reliability in fabrication of high-quality single crystal wafers. Since semiconductors by definition already have point defects, some may be used for purposes like single-photon sources.{{citation needed|date=December 2022}}

When studied at the single defect level, single emitters could be isolated. As a result of this, silicon carbide color centers can be used for applications in quantum cryptography protocols. One example of this was a study on nitrogen-vacancy centers in diamonds in 2014, which are similar to color centers in silicon carbide, that showcased novel results on how in diamonds, the nitrogen-vacancy were color centers, which also are fluorescent impurities that have many applications {{Cite journal |last1=Schirhagl |first1=Romana |last2=Chang |first2=Kevin |last3=Loretz |first3=Michael |last4=Degen |first4=Christian L. |date=2014-04-01 |title=Nitrogen-Vacancy Centers in Diamond: Nanoscale Sensors for Physics and Biology |url=https://www.annualreviews.org/doi/10.1146/annurev-physchem-040513-103659 |journal=Annual Review of Physical Chemistry |language=en |volume=65 |issue=1 |pages=83–105 |doi=10.1146/annurev-physchem-040513-103659 |pmid=24274702 |bibcode=2014ARPC...65...83S |issn=0066-426X}}

Quantum entanglement between the electron spin state and the single photon quantum state occurs when two conditions are met:

1. The quantum state of a single photon can be correlated to the electron spin state of the silicon carbide color centers
2. This correlation is able to be stored in nearby nuclear spins in the color centers

This quantum entanglement allows the creation of quantum networks, which leads to quantum communications, quantum memory, and metrology.

When the color centers are first brought to an excited state, a photon can be emitted from the decay from the excited state to the ground states. This photon can then interact with other sources of static and variable magnetic fields. As a result of this, the spin transition frequency and the coherence time are altered, which then this effect is used in quantum sensing.

Much of the color center research was originally performed using diamond instead of silicon carbide. For comparison, the nitrogen-vacancy in diamond has similar quantum properties to the divacancy in silicon carbide. Diamond's vacancy potentially has better quantum properties than silicon carbide's, but one of the major benefits of silicon carbide and its color centers is increased scalability and greater ease of manufacture when compared to diamond. Additionally, silicon carbide does not suffer from complications in production such as graphitization during irradiation which is possible during diamond color center manufacture.{{citation needed|date=December 2022}}

{{Reflist}}

Category:Wikipedia Student Program

Category:Crystallographic defects