Editing Spintronics (section)

==Spintronic-logic devices==
Non-volatile spin-logic devices to enable scaling are being extensively studied.<ref>[[International Technology Roadmap for Semiconductors]]</ref> Spin-transfer, torque-based logic devices that use spins and magnets for information processing have been proposed.<ref>{{Cite journal | last1 = Behin-Aein | first1 = B. | last2 = Datta | first2 = D. | last3 = Salahuddin | first3 = S. | last4 = Datta | first4 = S. | title = Proposal for an all-spin logic device with built-in memory | doi = 10.1038/nnano.2010.31 | journal = Nature Nanotechnology | volume = 5 | issue = 4 | pages = 266–270 | year = 2010 | pmid =  20190748|bibcode = 2010NatNa...5..266B }}</ref><ref>Manipatruni, Sasikanth; Nikonov, Dmitri E. and Young, Ian A. (2011) [https://arxiv.org/abs/1112.2746 [1112.2746&#93; Circuit Theory for SPICE of Spintronic Integrated Circuits]. Arxiv.org. Retrieved on 21 October 2013.</ref> These devices are part of the [[International Technology Roadmap for Semiconductors|ITRS]] exploratory road map. Logic-in memory applications are already in the development stage.<ref>[https://archive.today/20120420160205/http://crocus-technology.com/pr-12-08-11.html Crocus Partners With Starchip To Develop System-On-Chip Solutions Based on Magnetic-Logic-Unit (MLU) Technology]. crocus-technology.com. 8 December 2011</ref><ref>[http://www.nec.com/en/press/201206/global_20120611_02.html Groundbreaking New Technology for Improving the Reliability of Spintronics Logic Integrated Circuits]. Nec.com. 11 June 2012.</ref> A 2017 review article can be found in ''Materials Today''.<ref name="Bhatti et al." />

A generalized circuit theory for spintronic integrated circuits has been proposed<ref>S. Manipatruni, D. E. Nikonov and I. A. Young, "Modeling and Design of Spintronic Integrated Circuits," in IEEE Transactions on Circuits and Systems I: Regular Papers, vol. 59, no. 12, pp. 2801–2814, Dec. 2012, doi: 10.1109/TCSI.2012.2206465.  https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6359950&isnumber=6359940</ref> so that the physics of spin transport can be utilized by SPICE developers and subsequently by circuit and system designers for the exploration of spintronics for "beyond CMOS computing".

===Applications===
[[Disk read-and-write head|Read heads]] of magnetic [[hard drive]]s are based on the GMR or TMR effect.

Motorola developed a first-generation 256&nbsp;[[kilobit|kb]] [[magnetoresistive random-access memory]] (MRAM) based on a single magnetic tunnel junction and a single transistor that has a read/write cycle of under 50 nanoseconds.<ref>[http://www.sigmaaldrich.com/materials-science/alternative-energy-materials/magnetic-materials/tutorial/spintronics.html Spintronics]. Sigma-Aldrich. Retrieved on 21 October 2013.</ref> [[Everspin]] has since developed a 4&nbsp;[[Megabit|Mb]] version.<ref>[http://www.everspin.com/technology.php Everspin] {{webarchive |url=https://web.archive.org/web/20120630001137/http://www.everspin.com/technology.php |date=30 June 2012 }}. Everspin. Retrieved on 21 October 2013.</ref> Two second-generation MRAM techniques are in development: [[thermal-assisted switching]] (TAS)<ref>Hoberman, Barry. [http://www.crocustechnology.com/pdf/BH%20GSA%20Article.pdf The Emergence of Practical MRAM] {{webarchive|url=https://web.archive.org/web/20131021115241/http://www.crocustechnology.com/pdf/BH%20GSA%20Article.pdf |date=21 October 2013 }}. crocustechnology.com</ref> and [[spin-transfer torque]] (STT).<ref>LaPedus, Mark (18 June 2009) [http://www.eetimes.com/document.asp?doc_id=1171188 Tower invests in Crocus, tips MRAM foundry deal]. eetimes.com</ref>

Another design, [[racetrack memory]], a novel memory architecture proposed by [[Stuart Parkin|Dr. Stuart S. P. Parkin]], encodes information in the direction of magnetization between domain walls of a ferromagnetic wire.

In 2012, persistent spin helices of synchronized electrons were made to persist for more than a nanosecond, a 30-fold increase over earlier efforts, and longer than the duration of a modern processor clock cycle.<ref>{{cite journal|author=Walser, M.|author2=Reichl, C.|author3=Wegscheider, W.|author4=Salis, G.|name-list-style=amp |title=Direct mapping of the formation of a persistent spin helix|journal=Nature Physics|doi=10.1038/nphys2383|bibcode = 2012NatPh...8..757W|date=2012|volume=8|issue=10|pages=757 |arxiv=1209.4857|s2cid=119209785}}</ref>