Content deleted Content added
link to models |
Roberto DR (talk | contribs) →Advent of quantum mechanics: Fixed error in Ising order ansent in 1 dimension Tags: Reverted Mobile edit Mobile web edit |
||
Line 33:
In 1879, [[Edwin Herbert Hall]] working at the [[Johns Hopkins University]] discovered a voltage developed across conductors transverse to an electric current in the conductor and magnetic field perpendicular to the current.<ref>{{cite journal|title=On a New Action of the Magnet on Electric Currents|author=Hall, Edwin|journal=American Journal of Mathematics|volume=2|year=1879|pages=287–92|url=http://www.stenomuseet.dk/skoletj/elmag/kilde9.html|access-date=2008-02-28|doi=10.2307/2369245|issue=3|jstor=2369245|s2cid=107500183 |url-status=dead|archive-url=https://web.archive.org/web/20070208040346/http://www.stenomuseet.dk/skoletj/elmag/kilde9.html|archive-date=2007-02-08}}</ref> This phenomenon arising due to the nature of charge carriers in the conductor came to be termed the [[Hall effect]], but it was not properly explained at the time, since the electron was not experimentally discovered until 18 years later. After the advent of quantum mechanics, [[Lev Landau]] in 1930 developed the theory of [[Landau quantization]] and laid the foundation for the theoretical explanation for the [[quantum Hall effect]] discovered half a century later.<ref>{{cite book|first1=L. D.|last1=Landau|first2=E. M.|last2=Lifshitz|title=Quantum Mechanics: Nonrelativistic Theory|year=1977|publisher=Pergamon Press|isbn=978-0-7506-3539-4}}</ref>{{rp|458–460}}<ref>{{cite journal|title=Focus: Landmarks—Accidental Discovery Leads to Calibration Standard|date=2015-05-15|first=David|last=Lindley|journal=Physics|volume=8|page=46 |doi=10.1103/Physics.8.46}}</ref>
Magnetism as a property of matter has been known in China since 4000 BC.<ref name=mattis-magnetism-2006>{{cite book|last=Mattis|first=Daniel|title=The Theory of Magnetism Made Simple|year=2006|publisher=World Scientific|isbn=978-981-238-671-7}}</ref>{{rp|1–2}} However, the first modern studies of magnetism only started with the development of [[electrodynamics]] by Faraday, [[James Clerk Maxwell|Maxwell]] and others in the nineteenth century, which included classifying materials as [[ferromagnetic]], [[paramagnetic]] and [[diamagnetic]] based on their response to magnetization.<ref name=Chatterjee-2004-ferromagnetism>{{cite journal|last=Chatterjee|first=Sabyasachi|title=Heisenberg and Ferromagnetism|journal=Resonance|date=August 2004|volume=9|issue=8|doi=10.1007/BF02837578|url=http://www.ias.ac.in/describe/article/reso/009/08/0057-0066|access-date=13 June 2012|pages=57–66|s2cid=123099296}}</ref> [[Pierre Curie]] studied the dependence of magnetization on temperature and discovered the [[Curie point]] phase transition in ferromagnetic materials.<ref name=mattis-magnetism-2006 /> In 1906, [[Pierre Weiss]] introduced the concept of [[magnetic domain]]s to explain the main properties of ferromagnets.<ref name=Visintin-domains>{{cite book|last=Visintin|first=Augusto|title=Differential Models of Hysteresis|year=1994|publisher=Springer|isbn=978-3-540-54793-8|url=https://books.google.com/books?id=xZrTIDmNOlgC&pg=PA9}}</ref>{{rp|9}} The first attempt at a microscopic description of magnetism was by [[Wilhelm Lenz]] and [[Ernst Ising]] through the [[Ising model]] that described magnetic materials as consisting of a periodic lattice of [[Spin (physics)|spins]] that collectively acquired magnetization.<ref name=mattis-magnetism-2006/> The Ising model was solved exactly to show that [[spontaneous magnetization]]
===Modern many-body physics===
| |||