View source for Room-temperature superconductor

{{Short description|Material which exhibits superconductivity above 0 °C}}
{{Use dmy dates|date=November 2025}}
{{Unsolved|physics|Is it possible to make a material that is a superconductor at room temperature and atmospheric pressure?}}

A '''room-temperature superconductor''' is a hypothetical material capable of displaying [[superconductivity]] above {{cvt|0|C|K F}}, [[operating temperature]]s which are commonly encountered in everyday settings. {{As of|2023}}, the material with the highest accepted superconducting temperature was highly pressurized [[lanthanum decahydride]], whose [[transition temperature]] is approximately {{convert|250|K|°C F}} at 150&nbsp;GPa.<ref name="hemley" /><ref name="eremets" />

At standard [[atmospheric pressure]], [[High-temperature superconductor#Cuprates|cuprates]] currently hold the temperature record, manifesting superconductivity at temperatures as high as {{convert|138|K|°C F}}.<ref>{{cite journal |last1=Dai |first1=Pengcheng |last2=Chakoumakos |first2=Bryan C. |last3=Sun |first3=G.F. |last4=Wong |first4=Kai Wai |last5=Xin |first5=Ying |last6=Lu |first6=D.F. |year=1995 |title=Synthesis and neutron powder diffraction study of the superconductor HgBa<sub>2</sub>Ca<sub>2</sub>Cu<sub>3</sub>O<sub>8+δ</sub> by Tl substitution |journal=Physica C |volume=243 |issue=3–4 |pages=201–206 |bibcode=1995PhyC..243..201D |doi=10.1016/0921-4534(94)02461-8}}</ref> Over time, researchers have consistently encountered superconductivity at temperatures previously considered unexpected or impossible, challenging the notion that achieving superconductivity at room temperature was infeasible.<ref>{{cite journal |last1=Geballe |first1=Theodore Henry |author-link=Theodore H. Geballe |date=12 March 1993 |title=Paths to Higher Temperature Superconductors |journal=Science |volume=259 |issue=5101 |pages=1550–1551 |bibcode=1993Sci...259.1550G |doi=10.1126/science.259.5101.1550 |pmid=17733017}}</ref><ref name="almaden">{{cite web |last1=Jones |first1=Barbara A. |author-link=Barbara A. Jones |last2=Roche |first2=Kevin P. |date=25 July 2016 |title=Almaden Institute 2012: Superconductivity 297&nbsp;K&nbsp;– Synthetic Routes to Room Temperature Superconductivity |url=https://researcher.watson.ibm.com/researcher/view_project.php?id=3702 |archive-url=https://web.archive.org/web/20131212051851/http://researcher.watson.ibm.com/researcher/view_project.php?id=3702 |archive-date=12 December 2013 |access-date=18 September 2018 |work=researcher.watson.ibm.com}}</ref> The concept of "near-room temperature" transient effects has been a subject of discussion since the early 1950s.

== Reports ==
Since the discovery of [[high-temperature superconductivity|high-temperature superconductor]]s ("high" being temperatures above {{convert|77|K}}, the boiling point of [[liquid nitrogen]]), several materials have been claimed, although not confirmed, to be room-temperature superconductors.<ref>{{Cite web |last=Garisto |first=Dan |title=Viral New Superconductivity Claims Leave Many Scientists Skeptical |url=https://www.scientificamerican.com/article/viral-new-superconductivity-claims-leave-many-scientists-skeptical/ |date=July 27, 2023 |access-date=2023-07-28 |website=Scientific American |language=en |archive-date=27 July 2023 |archive-url=https://web.archive.org/web/20230727210945/https://www.scientificamerican.com/article/viral-new-superconductivity-claims-leave-many-scientists-skeptical/ |url-status=live }}</ref>

=== Corroborated studies ===
In 2014, an article published in ''[[Nature (journal)|Nature]]'' suggested that some materials, notably YBCO ([[yttrium barium copper oxide]]), could be made to briefly superconduct at room temperature using [[infrared laser]] pulses.<ref>
{{cite journal |last1=Mankowsky |first1=Roman |last2=Subedi |first2=Alaska |last3=Först |first3=Michael |last4=Mariager |first4=Simon O. |last5=Chollet |first5=Matthieu |last6=Lemke |first6=Henrik T. |last7=Robinson |first7=Joseph Stephen |last8=Glownia |first8=James M. |last9=Minitti |first9=Michael P. |last10=Frano |first10=Alex |last11=Fechner |first11=Michael |last12=Spaldin |first12=Nicola Ann |author12-link=Nicola Spaldin |last13=Loew |first13=Toshinao |last14=Keimer |first14=Bernhard |last15=Georges |first15=Antoine |year=2014 |title=Nonlinear lattice dynamics as a basis for enhanced superconductivity in YBa<sub>2</sub>Cu<sub>3</sub>O<sub>6.5</sub> |journal=[[Nature (journal)|Nature]] |volume=516 |issue=7529 |pages=71–73 |arxiv=1405.2266 |bibcode=2014Natur.516...71M |doi=10.1038/nature13875 |pmid=25471882 |s2cid=3127527 |first16=Andrea |last16=Cavalleri}}</ref>

In 2015, an article published in ''Nature'' by researchers of the [[Max Planck Institute for Chemistry|Otto Hahn Institute]] suggested that under certain conditions such as extreme pressure {{chem|[[Hydrogen|H]]|2|[[Sulfur|S]]}} transitioned to a superconductive form {{chem|H|3|[[Sulfur|S]]}} at 150&nbsp;GPa (around 1.5 million times atmospheric pressure) in a [[diamond anvil cell]].<ref>{{Cite journal |last1=Drozdov |first1=A. P. |last2=Eremets |first2=M. I. |last3=Troyan |first3=I. A. |last4=Ksenofontov |first4=V. |last5=Shylin |first5=S. I. |date=2015 |title=Conventional superconductivity at 203 kelvin at high pressures in the sulfur hydride system |url=http://www.nature.com/articles/nature14964 |url-status=live |journal=Nature |language=en |volume=525 |issue=7567 |pages=73–76 |arxiv=1506.08190 |bibcode=2015Natur.525...73D |doi=10.1038/nature14964 |issn=0028-0836 |pmid=26280333 |s2cid=4468914 |archive-url=https://web.archive.org/web/20210506223736/https://www.nature.com/articles/nature14964 |archive-date=6 May 2021 |access-date=9 June 2021}}</ref> The critical temperature is {{convert|203|K|°C}} which would be the highest ''T''<sub>c</sub> ever recorded and their research suggests that [[polyhydrides|other hydrogen compounds]] could superconduct at up to {{convert|260|K|°C}}.<ref name="cart15">{{cite journal |last1=Cartlidge |first1=Edwin |date=18 August 2015 |title=Superconductivity record sparks wave of follow-up physics |journal=Nature |volume=524 |issue=7565 |page=277 |bibcode=2015Natur.524..277C |doi=10.1038/nature.2015.18191 |pmid=26289188 |doi-access=free}}</ref><ref name="GeZhangYao2016">{{Cite journal |last1=Ge |first1=Yanfeng |last2=Zhang |first2=Fan |last3=Yao |first3=Yugui |year=2016 |title=First-principles demonstration of superconductivity at {{convert|280|K|°C}} in hydrogen sulfide with low phosphorus substitution |url=https://zenodo.org/record/1042765 |url-status=live |journal=Phys. Rev. B |volume=93 |issue=22 |article-number=224513 |arxiv=1507.08525 |bibcode=2016PhRvB..93v4513G |doi=10.1103/PhysRevB.93.224513 |s2cid=118730557 |archive-url=https://web.archive.org/web/20171107055957/https://zenodo.org/record/1042765 |archive-date=7 November 2017 |access-date=6 November 2017}}</ref>

Also in 2018, researchers noted a possible superconducting phase at {{convert|260|K|C}} in [[lanthanum decahydride]] ({{chem|[[Lanthanum|La]]|H|10}}) at elevated (200&nbsp;[[Pascal (unit)|GPa]]) pressure.<ref>{{Cite journal |last=Grant |first=Andrew |date=23 August 2018 |title=Pressurized superconductors approach room-temperature realm |journal=Physics Today |issue=8 |article-number=30438 |doi=10.1063/PT.6.1.20180823b |bibcode=2018PhT..2018h0438G |s2cid=240297717}}</ref> In 2019, the material with the highest accepted superconducting temperature was highly pressurized lanthanum decahydride, whose [[transition temperature]] is approximately {{convert|250|K|°C}} at 150&nbsp;GPa.<ref name="hemley">{{cite journal |last1=Somayazulu |first1=Maddury |last2=Ahart |first2=Muhtar |last3=Mishra |first3=Ajay Kumar |last4=Geballe |first4=Zachary M. |last5=Baldini |first5=Maria |last6=Meng |first6=Yue |last7=Struzhkin |first7=Viktor V. |last8=Hemley |first8=Russell Julian |author-link8=Russell J. Hemley |date=2019 |title=Evidence for Superconductivity above 260&nbsp;K in Lanthanum Superhydride at Megabar Pressures |journal=Phys. Rev. Lett. |volume=122 |issue=2 |article-number=027001 |arxiv=1808.07695 |bibcode=2019PhRvL.122b7001S |doi=10.1103/PhysRevLett.122.027001 |pmid=30720326 |s2cid=53622077}}</ref><ref name="eremets">{{cite journal |last1=Drozdov |first1=Alexander P. |last2=Kong |first2=Panpan |last3=Minkov |first3=Vasily S. |last4=Besedin |first4=Stanislav P. |last5=Kuzovnikov |first5=Mikhail A. |last6=Mozaffari |first6=Shirin |last7=Balicas |first7=Luis |last8=Balakirev |first8=Fedor F. |last9=Graf |first9=David E. |last10=Prakapenka |first10=Vitali B. |last11=Greenberg |first11=Eran |last12=Knyazev |first12=Dmitry A. |last13=Tkacz |first13=Marek |last14=Eremets |first14=Mikhail Ivanovich |author-link14=Mikhail Eremets |year=2019 |title=Superconductivity at 250 K in lanthanum hydride under high pressures |journal=Nature |volume=569 |issue=7757 |pages=528–531 |arxiv=1812.01561 |bibcode=2019Natur.569..528D |doi=10.1038/s41586-019-1201-8 |pmid=31118520 |s2cid=119231000}}</ref>

Though not room temperature, a rare earth 'infinite layer' nickelate was recently discovered that superconducted at the unheard of (for nickelates) temperature of 44K at ambient pressure. This material is stable in air unlike cuprates, and other nickelates may have even higher critical temperatures. The current theory is that these materials leverage very unusual physics including pair density waves (PDW) that may not be as sensitive to the normal pitfalls of high temperature superconductors like low critical current.<ref>{{cite journal | url=https://www.nature.com/articles/s41586-025-08755-z | doi=10.1038/s41586-025-08755-z | title=Ambient-pressure superconductivity onset above 40 K in (La,Pr)3Ni2O7 films | date=2025 | last1=Zhou | first1=Guangdi | last2=Lv | first2=Wei | last3=Wang | first3=Heng | last4=Nie | first4=Zihao | last5=Chen | first5=Yaqi | last6=Li | first6=Yueying | last7=Huang | first7=Haoliang | last8=Chen | first8=Wei-Qiang | last9=Sun | first9=Yu-Jie | last10=Xue | first10=Qi-Kun | last11=Chen | first11=Zhuoyu | journal=Nature | volume=640 | issue=8059 | pages=641–646 | pmid=39961334 | arxiv=2412.16622 }}</ref>

=== Uncorroborated studies ===
In 1993 and 1997, Michel Laguës and his team published evidence of room temperature superconductivity observed on [[Molecular Beam Epitaxy]] (MBE) deposited ultrathin [[nanostructure]]s of [[bismuth strontium calcium copper oxide]] (BSCCO, pronounced bisko, [[bismuth|Bi]]<sub>2</sub>[[strontium|Sr]]<sub>2</sub>[[calcium|Ca]]<sub>''n''−1</sub>[[copper|Cu]]<sub>''n''</sub>[[oxygen|O]]<sub>2''n''+4+''x''</sub>).<ref>Laguës et al. "Evidence suggesting superconductivity at 250&nbsp;K in a sequentially deposited cuprate film" Science  262, 1850 (1993)</ref><ref> Laguës et al. "Room temperature transport properties of new BiSrCaCuO compounds" C.R.Acad.Sci. Paris,  324,  627 (1997)</ref> These compounds exhibit extremely low resistivities orders of magnitude below that of copper, strongly non-linear I(V) characteristics and hysteretic I(V) behavior.   

In 2000, while extracting electrons from [[diamond]] during [[ion implantation]] work, South African physicist Johan Prins claimed to have observed a phenomenon that he explained as room-temperature superconductivity within a [[Phase (matter)|phase]] formed on the surface of oxygen-doped type [[Diamond|IIa diamonds]] in a [[Vacuum|{{nowrap|10<sup>−6</sup>&nbsp;mbar}} vacuum]].<ref>{{cite journal |last1=Prins |first1=Johan F. |date=1 March 2003 |title=The diamond vacuum interface: II. Electron extraction from n-type diamond: evidence for superconduction at room temperature |journal=Semiconductor Science and Technology |volume=18 |issue=3 |pages=S131–S140 |bibcode=2003SeScT..18S.131P |doi=10.1088/0268-1242/18/3/319 |s2cid=250881569}}</ref>

In 2003, a group of researchers published results on high-temperature superconductivity in [[palladium hydride]] (PdH<sub>''x''</sub>: {{nowrap|''x'' > 1}})<ref name="Tripodi2003">{{Cite journal |last1=Tripodi |first1=Paolo |last2=Di Gioacchino |first2=Daniele |last3=Borelli |first3=Rodolfo |last4=Vinko |first4=Jenny Darja |date=May 2003 |title=Possibility of high temperature superconducting phases in PdH |journal=Physica C |volume=388–389 |pages=571–572 |bibcode=2003PhyC..388..571T |doi=10.1016/S0921-4534(02)02745-4}}</ref> and an explanation in 2004.<ref name="Tripodi2004">{{Cite journal |last1=Tripodi |first1=Paolo |last2=Di Gioacchino |first2=Daniele |last3=Vinko |first3=Jenny Darja |date=August 2004 |title=Superconductivity in PdH: Phenomenological explanation |journal=Physica C |volume=408–410 |pages=350–352 |bibcode=2004PhyC..408..350T |doi=10.1016/j.physc.2004.02.099}}</ref> In 2007, the same group published results suggesting a superconducting transition temperature of 260&nbsp;K,<ref name="Tripodi2007">{{cite journal |last1=Tripodi |first1=Paolo |last2=Di Gioacchino |first2=Daniele |last3=Vinko |first3=Jenny Darja |year=2007 |title=A review of high temperature superconducting property of PdH system |journal=[[International Journal of Modern Physics#B|International Journal of Modern Physics B]] |volume=21 |issue=18&19 |pages=3343–3347 |bibcode=2007IJMPB..21.3343T |doi=10.1142/S0217979207044524}}</ref> with transition temperature increasing as the density of hydrogen inside the palladium lattice increases. This has not been corroborated by other groups.

In March 2021, an announcement reported superconductivity in a layered yttrium-palladium-hydron material at 262&nbsp;K and a pressure of 187&nbsp;GPa. Palladium may act as a hydrogen migration catalyst in the material.<ref>{{Cite web |title=A material that is superconductive at room temperature and lower pressure |url=https://phys.org/news/2021-03-material-superconductive-room-temperature-pressure.html |url-status=live |archive-url=https://web.archive.org/web/20210322180300/https://phys.org/news/2021-03-material-superconductive-room-temperature-pressure.html |archive-date=22 March 2021 |access-date=22 March 2021}}</ref><!-- Best to wait until a secondary source reports this ----  IFL also reported this -->

On 31 December 2023, "Global Room-Temperature Superconductivity in Graphite" was published in the journal ''Advanced Quantum Technologies'', claiming to demonstrate superconductivity at room temperature and ambient pressure in [[highly oriented pyrolytic graphite]] with dense arrays of nearly parallel line defects.<ref>{{cite journal | url=https://onlinelibrary.wiley.com/doi/10.1002/qute.202300230?ref=upstract.com | doi=10.1002/qute.202300230 | title=Global Room-Temperature Superconductivity in Graphite | date=2023 | last1=Kopelevich | first1=Yakov | last2=Torres | first2=José | last3=Da Silva | first3=Robson | last4=Oliveira | first4=Felipe | last5=Diamantini | first5=Maria Cristina | last6=Trugenberger | first6=Carlo | last7=Vinokur | first7=Valerii | journal=Advanced Quantum Technologies | volume=7 | issue=2 | article-number=2300230 | arxiv=2208.00854 }}</ref>

=== Retracted or unreliable studies ===
[[File:Magnet 4.jpg|alt=A magnet is suspended over a liquid nitrogen cooled high-temperature superconductor (−200&nbsp;°C)|thumb|A [[Magnetic levitation|magnet levitating]] above a superconductor (at −200&nbsp;°C) that is exhibiting the [[Meissner effect]].]]

In 2012, an ''[[Advanced Materials]]'' article claimed superconducting behavior of [[graphite]] powder after treatment with pure water at temperatures as high as 300&nbsp;K and above.<ref>
{{cite journal |last1=Scheike |first1=Thomas |last2=Böhlmann |first2=Winfried |last3=Esquinazi |first3=Pablo |last4=Barzola-Quiquia |first4=José |last5=Ballestar |first5=Ana |last6=Setzer |first6=Annette |year=2012 |title=Can Doping Graphite Trigger Room Temperature Superconductivity? Evidence for Granular High-Temperature Superconductivity in Water-Treated Graphite Powder |journal=Advanced Materials |volume=24 |issue=43 |pages=5826–5831 |arxiv=1209.1938 |bibcode=2012AdM....24.5826S |doi=10.1002/adma.201202219 |pmid=22949348 |s2cid=205246535}}</ref>{{Unreliable source?|date=May 2019}} So far, the authors have not been able to demonstrate the occurrence of a clear [[Meissner effect|Meissner]] phase and the vanishing of the material's resistance.

In 2018, Dev Kumar Thapa and Anshu Pandey from the Solid State and Structural Chemistry Unit of the [[Indian Institute of Science]], Bangalore claimed the observation of superconductivity at ambient pressure and room temperature in films and pellets of a nanostructured material that is composed of silver particles embedded in a gold matrix.<ref>{{cite arXiv |first1=Dev Kumar |last1=Thapa |first2=Anshu |last2=Pandey |date=2018 |title=Evidence for superconductivity at ambient temperature and pressure in nanostructures |eprint=1807.08572 |class=cond-mat.supr-con}}</ref> Due to similar noise patterns of supposedly independent plots and the publication's lack of [[peer review]], the results have been called into question.<ref>{{cite news |url=https://www.thehindu.com/sci-tech/science/iisc-duos-claim-of-ambient-superconductivity-may-have-support-in-theory/article24725793.ece |title=IISc duo's claim of ambient superconductivity may have support in theory |last=Desikan |first=Shubashree |date=18 August 2018 |newspaper=[[The Hindu]] |access-date=4 October 2018 |archive-date=24 June 2020 |archive-url=https://web.archive.org/web/20200624203521/https://www.thehindu.com/sci-tech/science/iisc-duos-claim-of-ambient-superconductivity-may-have-support-in-theory/article24725793.ece |url-status=live }}</ref> Although the researchers repeated their findings in a later paper in 2019,<ref>{{Cite news|url=https://www.thehindu.com/sci-tech/science/finally-iisc-team-confirms-superconductivity-at-room-temperature-pressure/article27246496.ece|title=Finally, IISc team confirms breakthrough in superconductivity at room temperature|first1=R.|last1=Prasad|first2=Shubashree|last2=Desikan|date=25 May 2019|via=www.thehindu.com|newspaper=The Hindu|access-date=26 May 2019|archive-date=26 May 2019|archive-url=https://web.archive.org/web/20190526084605/https://www.thehindu.com/sci-tech/science/finally-iisc-team-confirms-superconductivity-at-room-temperature-pressure/article27246496.ece|url-status=live}}</ref> this claim is yet to be verified and confirmed.{{Citation needed|date=October 2020}}

Since 2016, a team led by [[Ranga P. Dias]] has produced a number of retracted or challenged papers in this field. In 2016 they [[Metallic hydrogen#Claimed observation of solid metallic hydrogen, 2016|claimed observation of solid metallic hydrogen]].<ref>{{Cite journal |last=Garisto |first=Dan |date=2023-03-09 |title=Allegations of Scientific Misconduct Mount as Physicist Makes His Biggest Claim Yet |url=https://physics.aps.org/articles/v16/40 |url-status=live |journal=Physics |language=en |volume=16 |article-number=40 |bibcode=2023PhyOJ..16...40G |doi=10.1103/Physics.16.40 |s2cid=257615348 |archive-url=https://web.archive.org/web/20230321051328/https://physics.aps.org/articles/v16/40 |archive-date=21 March 2023 |access-date=21 March 2023|doi-access=free }}</ref> In October 2020, they reported room-temperature superconductivity at 288&nbsp;K (at 15&nbsp;°C) in a [[carbonaceous sulfur hydride]] at 267&nbsp;GPa, triggered into crystallisation via green laser.<ref>{{cite news|title=Finally, the First Room-Temperature Superconductor|date=October 14, 2020|newspaper=The New York Times|first=Kenneth|last=Chang|url=https://www.nytimes.com/2020/10/14/science/superconductor-room-temperature.html|access-date=14 October 2020|archive-date=14 October 2020|archive-url=https://web.archive.org/web/20201014181828/https://www.nytimes.com/2020/10/14/science/superconductor-room-temperature.html|url-status=live}}</ref><ref>{{cite journal |last1=Snider |first1=Elliot |last2=Dasenbrock-Gammon |first2=Nathan |last3=McBride |first3=Raymond |last4=Debessai |first4=Mathew |last5=Vindana |first5=Hiranya |last6=Vencatasamy |first6=Kevin |last7=Lawler |first7=Keith V. |last8=Salamat |first8=Ashkan |last9=Dias |first9=Ranga P. |title=Room-temperature superconductivity in a carbonaceous sulfur hydride |journal=Nature |date=October 2020 |volume=586 |issue=7829 |pages=373–377 |doi=10.1038/s41586-020-2801-z |pmid=33057222 |bibcode=2020Natur.586..373S |osti=1673473 |s2cid=222823227 }}{{Retracted|doi=10.1038/s41586-022-05294-9|pmid=36163290|intentional=yes}}</ref> This was retracted in 2022 after flaws in their statistical methods were identified<ref>{{Cite journal |last1=van der Marel |first1=Dirk |last2=Hirsch |first2=Jorge E. |date=January 19, 2022 |title=Comment on Nature 586, 373 (2020) by E. Snider et al |journal=International Journal of Modern Physics B |volume=37 |issue=4 |page=2375001 |arxiv=2201.07686 |doi=10.1142/S0217979223750012 |issn=0217-9792 |s2cid=252324362}}</ref> and led to questioning of other data.<ref>{{cite news|title='Something is Seriously Wrong':Room-Temperature superconductivity study retracted|date=September 26, 2022|magazine=Science|first=Eric|last=Hand|url=https://www.science.org/content/article/something-seriously-wrong-room-temperature-superconductivity-study-retracted|access-date=27 September 2022|archive-date=27 September 2022|archive-url=https://web.archive.org/web/20220927165501/https://www.science.org/content/article/something-seriously-wrong-room-temperature-superconductivity-study-retracted|url-status=live}}</ref><ref>{{Cite journal |last1=Dasenbrock-Gammon |first1=Nathan |last2=Snider |first2=Elliot |last3=McBride |first3=Raymond |last4=Pasan |first4=Hiranya |last5=Durkee |first5=Dylan |last6=Khalvashi-Sutter |first6=Nugzari |last7=Munasinghe |first7=Sasanka |last8=Dissanayake |first8=Sachith E. |last9=Lawler |first9=Keith V. |last10=Salamat |first10=Ashkan |last11=Dias |first11=Ranga P. |date=9 March 2023 |title=Evidence of near-ambient superconductivity in a N-doped lutetium hydride |url=https://www.nature.com/articles/s41586-023-05742-0 |url-status=live |journal=Nature |volume=615 |issue=7951 |pages=244–250 |bibcode=2023Natur.615..244D |doi=10.1038/s41586-023-05742-0 |pmid=36890373 |s2cid=257407449 |archive-url=https://web.archive.org/web/20230308232103/https://www.nature.com/articles/s41586-023-05742-0 |archive-date=8 March 2023 |access-date=8 March 2023 |via=www.nature.com|url-access=subscription }}{{Retracted|doi=10.1038/s41586-023-06774-2|pmid=37935926|intentional=yes}}</ref><ref>{{Cite news |last=Woodward |first=Aylin |date=8 March 2023 |title=The Scientific Breakthrough That Could Make Batteries Last Longer |newspaper=Wall Street Journal |url=https://www.wsj.com/articles/superconductor-breakthrough-energy-reddmatter-90dfa165 |url-status=live |access-date=8 March 2023 |archive-url=https://web.archive.org/web/20230308223808/https://www.wsj.com/articles/superconductor-breakthrough-energy-reddmatter-90dfa165 |archive-date=8 March 2023}}</ref><ref>{{Cite web |title='Revolutionary' blue crystal resurrects hope of room temperature superconductivity |url=https://www.science.org/content/article/revolutionary-blue-crystal-resurrects-hope-room-temperature-superconductivity |url-status=live |archive-url=https://web.archive.org/web/20230308232240/https://www.science.org/content/article/revolutionary-blue-crystal-resurrects-hope-room-temperature-superconductivity |archive-date=8 March 2023 |access-date=8 March 2023 |website=www.science.org}}</ref><ref>{{Cite web |author=Anderson |first=Margo |date=March 8, 2023 |title=Room-Temperature Superconductivity Claimed |url=https://spectrum.ieee.org/room-temperature-superconductor |url-status=live |archive-url=https://web.archive.org/web/20230309180951/https://spectrum.ieee.org/room-temperature-superconductor |archive-date=9 March 2023 |access-date=9 March 2023 |website=[[IEEE Spectrum]] |publisher=[[Institute of Electrical and Electronics Engineers]]}}</ref><ref>{{cite web |last1=Wood |first1=Charlie |last2=Savitsky |first2=Zack |date=8 March 2023 |title=Room-Temperature Superconductor Discovery Meets With Resistance |url=https://www.quantamagazine.org/room-temperature-superconductor-discovery-meets-with-resistance-20230308/ |url-status=live |archive-url=https://web.archive.org/web/20230314204756/https://www.quantamagazine.org/room-temperature-superconductor-discovery-meets-with-resistance-20230308/ |archive-date=14 March 2023 |access-date=2023-03-14 |website=[[Quanta Magazine]] |publisher=[[Simons Foundation]]}}</ref> In 2023 he reported superconductivity at 294&nbsp;K and 1&nbsp;GPa in nitrogen-doped [[Lutetium hydride nitride|lutetium hydride]], in a paper widely met with skepticism about its methods and data. Later in 2023 he was found to have plagiarized parts of his dissertation from someone else's thesis, and to have fabricated data in a paper on [[manganese disulfide]], which was retracted.<ref>{{Cite journal |last=Garisto |first=Dan |date=2023-03-09 |title=Allegations of Scientific Misconduct Mount as Physicist Makes His Biggest Claim Yet |url=https://physics.aps.org/articles/v16/40 |journal=Physics |language=en |volume=16 |article-number=40|doi=10.1103/Physics.16.40 |bibcode=2023PhyOJ..16...40G |s2cid=257615348 |doi-access=free }}</ref> The lutetium hydride paper was also retracted.{{Citation needed|date=October 2020}} The first attempts to [[Reproducibility|replicate]] those results failed.<ref>{{Cite web |last=Yirka |first=Bob |date=17 May 2023 |title=Replication of room-temperature superconductor claims fails to show superconductivity |url=https://phys.org/news/2023-05-replication-room-temperature-superconductor-superconductivity.amp |url-status=live |archive-url=https://web.archive.org/web/20230618070842/https://phys.org/news/2023-05-replication-room-temperature-superconductor-superconductivity.amp |archive-date=18 June 2023 |access-date=18 June 2023}}</ref><ref>{{Cite web |last=Wilkins |first=Alex |date=17 March 2023 |title='Red matter' superconductor may not be a wonder material after all |url=https://www.newscientist.com/article/2364955-red-matter-superconductor-may-not-be-a-wonder-material-after-all/ |url-status=live |archive-url=https://web.archive.org/web/20230321051336/https://www.newscientist.com/article/2364955-red-matter-superconductor-may-not-be-a-wonder-material-after-all/ |archive-date=21 March 2023 |website=New Scientist |language=en-US}}</ref><ref>{{cite arXiv |eprint=2306.06301 |class=cond-mat |first1=Nilesh P. |last1=Salke |first2=Alexander C. |last2=Mark |title=Evidence for Near Ambient Superconductivity in the Lu-N-H System |date=2023-06-09 |last3=Ahart |first3=Muhtar |last4=Hemley |first4=Russell J.}}</ref>

On 23 July 2023, a Korean team claimed that Cu-doped lead apatite, which they named [[LK-99]], was superconducting up to 400&nbsp;K, though they had not observed this fully.<ref>{{cite arXiv |eprint=2307.12008 |class=cond-mat.supr-con |first1=Sukbae |last1=Lee |first2=Ji-Hoon |last2=Kim |title=The First Room-Temperature Ambient-Pressure Superconductor |date=2023 |last3=Kwon |first3=Young-Wan}}</ref> They posted two preprints to [[arXiv]],<ref>{{cite arXiv |eprint=2307.12037 |class=cond-mat.supr-con |first1=Sukbae |last1=Lee |first2=Jihoon |last2=Kim |title=Superconductor Pb10−xCux(PO4)6O showing levitation at room temperature and atmospheric pressure and mechanism |date=2023 |last3=Kim |first3=Hyun-Tak |last4=Im |first4=Sungyeon |last5=An |first5=SooMin |author6=Keun Ho Auh}}</ref> published a paper in a journal,<ref>{{cite journal |last1=Lee |first1=Sukbae |last2=Kim |first2=Jihoon |last3=Im |first3=Sungyeon |last4=An |first4=Soomin |last5=Kwon |first5=Young-Wan |last6=Ho |first6=Auh Keun |date=April 2023 |title=다음논문 Consideration for the development of room-temperature ambient-pressure superconductor (LK-99) |url=http://journal.kci.go.kr/jkcgct/archive/articleView?artiId=ART002955269 |url-status=live |journal=Journal of the Korean Crystal Growth and Crystal Technology |volume=33 |issue=2 |pages=61–70 |archive-url=https://web.archive.org/web/20230726083507/http://journal.kci.go.kr/jkcgct/archive/articleView?artiId=ART002955269 |archive-date=26 July 2023 |access-date=26 July 2023}}</ref> and submitted a patent application.<ref>{{cite web |title=Room temperature and normal pressure superconducting ceramic compound, and method for manufacturing same |url=https://patents.google.com/patent/WO2023027536A1/en?oq=WO2023027536A1 |url-status=live |archive-url=https://web.archive.org/web/20230726001509/https://patents.google.com/patent/WO2023027536A1/en?oq=WO2023027536A1 |archive-date=26 July 2023 |access-date=26 July 2023}}</ref> The reported observations were received with skepticism by experts due to the lack of clear signatures of superconductivity.<ref>{{cite magazine |last=Padavic-Callaghn |first=Karmela |date=26 July 2023 |title=Room-temperature superconductor 'breakthrough' met with scepticism |url=https://www.newscientist.com/article/2384782-room-temperature-superconductor-breakthrough-met-with-scepticism |magazine=[[New Scientist]] |access-date=26 July 2023}}</ref> The story was widely discussed on social media, leading to a large number of attempted replications, none of which had more than qualified success. By mid-August, a series of papers from major labs provided significant evidence that LK-99 was not a superconductor, finding resistivity much higher than copper, and explaining observed effects such as magnetic response and resistance drops in terms of impurities and ferromagnetism in the material.<ref>{{Cite news|title=A superconductor claim blew up online. Science has punctured it. |date=August 9, 2023 |last=Johnson |first=Carolyn |access-date=2023-08-09| newspaper=The Washington Post| url=https://www.washingtonpost.com/science/2023/08/09/room-temperature-superconductor-lk99-evidence/}}</ref><ref>{{cite magazine |last=Orf |first=Darren |date=Aug 9, 2023 |title=Well, Seems Like LK-99 Isn't a Room Temperature Superconductor After All |url=https://www.popularmechanics.com/science/green-tech/a44764458/lk-99-not-a-superconductor/ |magazine=Popular Mechanics |access-date=2023-08-09}}</ref>

== Theories ==
=== Metallic hydrogen and phonon-mediated pairing ===
Theoretical work by British physicist [[Neil Ashcroft]] predicted that solid [[metallic hydrogen]] at extremely high pressure (~500&nbsp;[[Pascal (unit)|GPa]]) should become superconducting at approximately room temperature, due to its extremely high [[speed of sound]] and expected strong [[coupling (physics)|coupling]] between the conduction electrons and the lattice-vibration [[phonon]]s.<ref name="Ashc1968">
{{cite journal
 |author = Ashcroft, N. W. 
 |title = Metallic Hydrogen: A High-Temperature Superconductor?
 |year = 1968  |journal = [[Physical Review Letters]]
 |volume = 21 |issue=26 |pages = 1748–1749  |doi = 10.1103/PhysRevLett.21.1748
 |bibcode = 1968PhRvL..21.1748A
}}</ref>

A team at [[Harvard University]] has claimed to make metallic hydrogen and reports a pressure of 495&nbsp;GPa.<ref>{{Cite web |url=https://www.independent.co.uk/news/science/hydrogen-metal-revolution-technology-space-rockets-superconductor-harvard-university-a7548221.html |title=Hydrogen turned into metal in stunning act of alchemy that could revolutionise technology and spaceflight |work=[[The Independent]] |language=en-UK |first=Ian |last=Johnston |date=26 January 2017 |access-date=12 December 2017 |archive-date=3 May 2019 |archive-url=https://web.archive.org/web/20190503185719/https://www.independent.co.uk/news/science/hydrogen-metal-revolution-technology-space-rockets-superconductor-harvard-university-a7548221.html |url-status=live }}</ref> Though the exact critical temperature has not yet been determined, weak signs of a possible Meissner effect and changes in magnetic susceptibility at 250 K may have appeared in early magnetometer tests on an original now-lost sample. A French team is working with doughnut shapes rather than planar at the diamond culette tips.<ref>{{Cite arXiv |eprint = 1906.05634|title = Observation of a first order phase transition to metal hydrogen near 425&nbsp;GPa|last1 = Loubeyre|first1 = Paul|last2 = Occelli|first2 = Florent|last3 = Dumas|first3 = Paul|year = 2019| class=cond-mat.mtrl-sci }}</ref>

=== Organic polymers and exciton-mediated pairing ===
In 1964, William A. Little proposed the possibility of high-temperature superconductivity in [[organic polymers]].<ref>{{cite journal
 |author = Little, W. A. 
 |title = Possibility of Synthesizing an Organic Superconductor
 |year = 1964  |journal = Physical Review
 |volume = 134 |issue = 6A
 |pages = A1416–A1424  |doi = 10.1103/PhysRev.134.A1416|bibcode = 1964PhRv..134.1416L }}</ref>

=== Other hydrides ===
In 2004, Ashcroft returned to his idea and suggested that hydrogen-rich compounds can become metallic and superconducting at lower pressures than hydrogen. More specifically, he proposed a novel way to pre-compress hydrogen chemically by examining [[IVa hydride]]s.<ref name=Ashc2004>
{{cite journal
 |author = Ashcroft, N. W. 
 |title = Hydrogen Dominant Metallic Alloys: High Temperature superconductors
 |year = 2004  |journal = [[Physical Review Letters]]
 |volume = 92 |issue=18 |pages = 1748–1749  |article-number = 187002
 |doi = 10.1103/PhysRevLett.92.187002|pmid = 15169525
 |bibcode = 2004PhRvL..92r7002A
}}</ref>

In 2014–2015, conventional superconductivity was observed in a sulfur hydride system ([[Hydrogen sulfide|{{chem|H|2|S}}]] or {{chem|H|3|S}}) at 190&nbsp;K to 203&nbsp;K at pressures of up to 200&nbsp;GPa.

In 2016, research suggested a link between [[palladium hydride]] containing small impurities of sulfur [[nanoparticle]]s as a plausible explanation for the anomalous transient resistance drops seen during some experiments, and hydrogen absorption by cuprates was suggested in light of the 2015 results in {{chem|link=Hydrogen sulfide|H|2|S}} as a plausible explanation for transient resistance drops or "USO" noticed in the 1990s by Chu ''et al.'' during research after the discovery of [[YBCO]].<ref>{{Cite thesis |url=https://research-repository.griffith.edu.au/handle/10072/367614 |title=Transient High-Temperature Superconductivity in Palladium Hydride |website=[[Griffith University]] |year=2016 |publisher=Griffith University |type=Griffith thesis |access-date=2 December 2019 |archive-date=6 August 2020 |archive-url=https://web.archive.org/web/20200806024508/https://research-repository.griffith.edu.au/handle/10072/367614 |url-status=live }}</ref>

It has been predicted that {{chem|[[Scandium|Sc]]|H|12}} ([[scandium dodecahydride]]) would exhibit superconductivity at room temperature – {{abbr|''T''<sub>c</sub>|Critical temperature}} between {{convert|333|K|°C}} and {{convert|398|K|°C}} – under a pressure expected not to exceed 100&nbsp;GPa.<ref>{{cite journal |arxiv=2302.02621 |first1=Qiwen |last1=Jiang |first2=Defang |last2=Duan |title=Prediction of Room-Temperature Superconductivity in Quasi-Atomic H<sub>2</sub>-Type Hydrides at High Pressure |date=2024 |last3=Song |first3=Hao |last4=Zhang |first4=Zihan |last5=Huo |first5=Zihao |last6=Cui |first6=Tian |last7=Yao |first7=Yansun|journal=Advanced Science |volume=11 |issue=35 |article-number=e2405561 |doi=10.1002/advs.202405561 |pmid=39033541 |pmc=11425200 }}</ref>

Some research efforts are currently moving towards [[Ternary compound|ternary]] [[Polyhydride#Superconduction|superhydrides]], where it has been predicted that {{chem|[[Lithium|Li]]|2|Mg|H|16}} ([[dilithium magnesium hexadecahydride]]) would have a {{abbr|''T''<sub>c</sub>|Critical temperature}} of {{convert|473|K|°C}} at 250&nbsp;GPa.<ref>{{cite journal |last1=Sun |first1=Ying |last2=Lv |first2=Jian |last3=Xie |first3=Yu |last4=Liu |first4=Hanyu |last5=Ma |first5=Yanming |date=August 26, 2019 |title=Route to a Superconducting Phase above Room Temperature in Electron-Doped Hydride Compounds under High Pressure |url=https://physics.aps.org/featured-article-pdf/10.1103/PhysRevLett.123.097001 |url-status=live |journal=Physical Review Letters |volume=123 |issue=9 |article-number=097001 |bibcode=2019PhRvL.123i7001S |doi=10.1103/PhysRevLett.123.097001 |pmid=31524448 |s2cid=202123043 |archive-url=https://web.archive.org/web/20201126015148/https://physics.aps.org/featured-article-pdf/10.1103/PhysRevLett.123.097001 |archive-date=26 November 2020 |access-date=9 January 2022 |quote=The recent theory-orientated discovery of record high-temperature superconductivity ({{abbr|''T''<sub>c</sub>|Critical temperature}}~250&nbsp;K) in sodalitelike clathrate LaH<sub>10</sub> is an important advance toward room-temperature superconductors. Here, we identify an alternative clathrate structure in ternary {{chem|[[Lithium|Li]]|2|Mg|H|16}} with a remarkably high estimated ''T''<sub>c</sub> of ~473&nbsp;K at 250&nbsp;GPa, which may allow us to obtain room-temperature or even higher-temperature superconductivity.|url-access=subscription }}</ref><ref>{{cite web |last=Extance |first=Andy |date=November 1, 2019 |title=The race is on to make the first room temperature superconductor |url=https://www.chemistryworld.com/news/the-race-is-on-to-make-the-first-room-temperature-superconductor/4010591.article |url-status=live |archive-url=https://web.archive.org/web/20191230182715/https://www.chemistryworld.com/news/the-race-is-on-to-make-the-first-room-temperature-superconductor/4010591.article |archive-date=30 December 2019 |access-date=December 30, 2019 |website=www.chemistryworld.com |publisher=Royal Society of Chemistry |quote=In August, Ma and colleagues published a study that showed the promise of ternary superhydrides. They predicted that {{chem|[[Lithium|Li]]|2|[[Magnesium|Mg]]|H|16}} would have a {{abbr|''T''<sub>c</sub>|Critical temperature}} of 473&nbsp;[[Kelvin|K]] at 250&nbsp;GPa, far in excess of room temperature.}}</ref>

=== Spin coupling ===
It is also possible that if the [[Bipolaron (physics)|bipolaron]] explanation is correct, a normally semiconducting material can transition under some conditions into a superconductor if a critical level of alternating spin coupling in a single plane within the lattice is exceeded; this may have been documented in very early experiments from 1986. The best analogy here would be anisotropic [[magnetoresistance]], but in this case the outcome is a drop to zero rather than a decrease within a very narrow temperature range for the compounds tested similar to "[[re-entrant superconductivity]]".<ref>{{cite journal | url=https://www.sciencedirect.com/science/article/abs/pii/S0921453406008094 | doi=10.1016/j.physc.2006.10.013 | bibcode=2007PhyC..451...86D | title=Superconductors with two critical temperatures | last1=Di Grezia | first1=E. | last2=Esposito | first2=S. | last3=Salesi | first3=G. | journal=Physica C | date=2007 | volume=451 | issue=2 | page=86 | arxiv=cond-mat/0607303 }}</ref>

In 2018, support was found for electrons having anomalous 3/2 [[Spin (physics)|spin states]] in YPtBi.<ref>{{cite web |url=https://www.sciencealert.com/brand-new-type-of-superconductor-discovered-physics |title=Physicists Just Discovered an Entirely New Type of Superconductivity |first=Fiona |last=MacDonald |date=9 April 2018 |work=ScienceAlert |access-date=6 February 2019 |archive-date=7 February 2019 |archive-url=https://web.archive.org/web/20190207072414/https://www.sciencealert.com/brand-new-type-of-superconductor-discovered-physics |url-status=live }}</ref> Though YPtBi is a relatively low temperature superconductor, this does suggest another approach to creating superconductors.<!--Also relevant to the above discussion:<ref>{{Cite web | url=https://phys.org/news/2020-02-quasi-particle-pi-ton.html |title = New quasi-particle discovered: Introducing the Pi-ton}}</ref> which suggests tentatively that a sufficiently complex lattice with the right internal geometry could indeed superconduct well above the "official" maximum ever observed for cuprates, 153&nbsp;K, if indeed flowing bipolarons composed of two electrons and two holes are able to sustain a [[supercurrent]].<ref>{{cite web |title=New advance in superconductors with 'twist' in rhombohedral graphite |url=https://phys.org/news/2020-08-advance-superconductors-rhombohedral-graphite.html |website=phys.org |language=en |date=August 2020}}</ref>--><ref>{{Cite journal|date=2018|title=Beyond triplet: Unconventional superconductivity in a spin-3/2 topological semimetal|journal=Science Advances|volume=4|issue=4|doi=10.1126/sciadv.aao4513|arxiv=1603.03375 |last1=Kim |first1=Hyunsoo |last2=Wang |first2=Kefeng |last3=Nakajima |first3=Yasuyuki |last4=Hu |first4=Rongwei |last5=Ziemak |first5=Steven |last6=Syers |first6=Paul |last7=Wang |first7=Limin |last8=Hodovanets |first8=Halyna |last9=Denlinger |first9=Jonathan D. |last10=Brydon |first10=Philip M. R. |last11=Agterberg |first11=Daniel F. |last12=Tanatar |first12=Makariy A. |last13=Prozorov |first13=Ruslan |last14=Paglione |first14=Johnpierre |article-number=eaao4513 |pmid=29740606 |pmc=5938259 |bibcode=2018SciA....4.4513K }}</ref>

"Quantum bipolarons" could describe how a material might superconduct at up to nearly room temperature.<ref>{{cite web | url=https://phys.org/news/2024-06-high-temperature-superconductivity-exploring-quadratic.html | title=High-temperature superconductivity: Exploring quadratic electron-phonon coupling }}</ref>

== References ==
{{reflist}}

{{Superconductivity}}

[[Category:Superconductors]]
[[Category:Hypothetical technology]]
[[Category:High pressure science]]