Editing Fractional quantum Hall effect (section)

== Impact ==
{{expand section|date=April 2019}}
The FQH effect shows the limits of [[Lev Landau|Landau]]'s [[symmetry breaking]] theory. Previously it was held that the symmetry breaking theory could explain all the important concepts and properties of forms of matter. According to this view, the only thing to be done was to apply the [[symmetry breaking]] theory to all different kinds of phases and [[phase transition]]s.<ref>{{cite journal |vauthors=Rychkov VS, Borlenghi S, Jaffres H, Fert A, Waintal X |title=Spin torque and waviness in magnetic multilayers: a bridge between Valet-Fert theory and quantum approaches |journal=Phys. Rev. Lett. |volume=103 |issue=6 |pages=066602 |date=August 2009 |pmid=19792592|doi=10.1103/PhysRevLett.103.066602|bibcode=2009PhRvL.103f6602R|arxiv = 0902.4360 |s2cid=209013 }}</ref> From this perspective, the importance of the FQHE discovered by
Tsui, Stormer, and Gossard is notable for contesting old perspectives.

The existence of FQH liquids suggests that there is much more to discover beyond the present [[symmetry breaking]] paradigm in condensed matter physics.
Different FQH states all have the same symmetry
and cannot be described by symmetry breaking theory.
The associated [[fractional charge]], [[fractional statistics]], [[Non-abelian gauge theory|non-Abelian]] statistics,
[[chiral]] edge states, etc. demonstrate the power and the fascination of [[emergence]] in many-body systems.
Thus FQH states represent new states of matter that contain a
completely new kind of order—[[topological order]].
For example, properties once deemed isotropic for all materials may be anisotropic in 2D planes.
The new type of orders represented by FQH states greatly enrich our
understanding of quantum phases and [[quantum phase transitions]].<ref>{{cite journal |author=Callaway DJE |author-link=David J E Callaway |title=Random matrices, fractional statistics, and the quantum Hall effect |journal=Phys. Rev. B |volume=43 |issue=10 |pages=8641–8643 |date=April 1991 |pmid=9996505 |doi=10.1103/PhysRevB.43.8641|bibcode = 1991PhRvB..43.8641C }}</ref><ref>{{Cite journal|last1=Selby|first1=N. S.|last2=Crawford|first2=M.|last3=Tracy|first3=L.|last4=Reno|first4=J. L.|last5=Pan|first5=W.|date=2014-09-01|title=In situ biaxial rotation at low-temperatures in high magnetic fields|journal=Review of Scientific Instruments|volume=85|issue=9|pages=095116|doi=10.1063/1.4896100|pmid=25273781|issn=0034-6748|bibcode=2014RScI...85i5116S|url=https://zenodo.org/record/1232073|doi-access=free}}</ref>