Editing Superconductivity (section)

=== Josephson effect ===
In 1962, [[Brian David Josephson|Josephson]] made the important theoretical prediction that a supercurrent can flow between two pieces of superconductor separated by a thin layer of insulator.<ref>{{cite journal |author=Josephson |first=B. D. |date=1962 |title=Possible new effects in superconductive tunnelling |journal=[[Physics Letters]] |volume=1 |issue=7 |pages=251–253 |bibcode=1962PhL.....1..251J |doi=10.1016/0031-9163(62)91369-0}}</ref> This phenomenon, now called the [[Josephson effect]], is exploited by superconducting devices such as [[SQUID|SQUIDs]]. It is used in the most accurate available measurements of the [[magnetic flux quantum]] ''Φ''<sub>0</sub>&nbsp;=&nbsp;''h''/(2''e''), where ''h'' is the [[Planck constant]]. Coupled with the [[Quantum Hall effect|quantum Hall resistivity]], this leads to a precise measurement of the Planck constant. Josephson was awarded the Nobel Prize for this work in 1973.<ref>{{Cite web |title=The Nobel Prize in Physics 1973 |url=https://www.nobelprize.org/prizes/physics/1973/summary/ |url-status=live |archive-url=https://web.archive.org/web/20210325040501/https://www.nobelprize.org/prizes/physics/1973/summary/ |archive-date=Mar 25, 2021 |access-date=2021-03-30 |website=[[Nobel Foundation|NobelPrize.org]] |language=en-US}}</ref>

In 2008, it was proposed that the same mechanism that produces superconductivity could produce a [[superinsulator]] state in some materials, with almost infinite [[electrical resistance]].<ref>{{cite web |date=April 9, 2008 |title=Newly discovered fundamental state of matter, a superinsulator, has been created. |url=https://www.sciencedaily.com/releases/2008/04/080408160614.htm |access-date=2008-10-23 |website=Science Daily}}</ref> The first development and study of superconducting [[Bose–Einstein condensate]] (BEC) in 2020 suggested a "smooth transition between" BEC and [[BCS theory|Bardeen-Cooper-Shrieffer]] regimes.<ref>{{cite news |title=Researchers demonstrate a superconductor previously thought impossible |url=https://phys.org/news/2020-11-superconductor-previously-thought-impossible.html |access-date=8 December 2020 |work=phys.org |language=en}}</ref><ref>{{cite journal |last1=Hashimoto |first1=Takahiro |last2=Ota |first2=Yuichi |last3=Tsuzuki |first3=Akihiro |last4=Nagashima |first4=Tsubaki |last5=Fukushima |first5=Akiko |last6=Kasahara |first6=Shigeru |last7=Matsuda |first7=Yuji |last8=Matsuura |first8=Kohei |last9=Mizukami |first9=Yuta |last10=Shibauchi |first10=Takasada |last11=Shin |first11=Shik |last12=Okazaki |first12=Kozo |date=1 November 2020 |title=Bose–Einstein condensation superconductivity induced by disappearance of the nematic state |url= |journal=Science Advances |language=en |volume=6 |issue=45 |pages=eabb9052 |bibcode=2020SciA....6.9052H |doi=10.1126/sciadv.abb9052 |issn=2375-2548 |pmc=7673702 |pmid=33158862}}</ref>