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Line 1: {{string theory}} In theoretical physics, ''' == Overview == Over the decades, [[experimental physics|experimental]] [[condensed matter]] physicists have discovered a number of exotic states of matter, including [[superconductors]] and [[superfluids]]. These states are described using the formalism of quantum field theory, but some phenomena are difficult to explain using standard field theoretic techniques. Some condensed matter theorists including [[Subir Sachdev]] hope that the AdS/CFT correspondence will make it possible to describe these systems in the language of string theory and learn more about their behavior.<ref name="Merali 2011, p.303">Merali 2011, p. 303</ref> So far some success has been achieved in using string theory methods to describe the transition of a [[superfluid]] to an [[insulator (electricity)|insulator]]. A superfluid is a system of [[electrically neutral]] [[atoms]] that flows without any [[friction]]. Such systems are often produced in the laboratory using [[liquid helium]], but recently experimentalists have developed new ways of producing artificial superfluids by pouring trillions of cold atoms into a lattice of criss-crossing [[lasers]]. These atoms initially behave as a superfluid, but as experimentalists increase the intensity of the lasers, they become less mobile and then suddenly transition to an insulating state. During the transition, the atoms behave in an unusual way. For example, the atoms slow to a halt at a rate that depends on the [[temperature]] and on the Planck == Criticism == Despite many physicists turning towards string-based methods to address problems in condensed matter physics{{fact|date=December 2016}}, some theorists working in this area have expressed doubts about whether the AdS/CFT correspondence can provide the tools needed to realistically model real-world systems. In a letter to [[Physics Today]], [[Nobel laureate]] [[Philip W. Anderson]] wrote {{quote|text="As a very general problem with the AdS/CFT approach in condensed-matter theory, we can point to those telltale initials "CFT"—conformal field theory. Condensed-matter problems are, in general, neither relativistic nor conformal. Near a quantum critical point, both time and space may be scaling, but even there we still have a preferred coordinate system and, usually, a lattice. There is some evidence of other linear-T phases to the left of the strange metal about which they are welcome to speculate, but again in this case the condensed-matter problem is overdetermined by experimental facts == See also == Line 19: * [[AdS/QCD correspondence]] == Notes == {{reflist}} == References == * {{cite journal | last1 = Merali | first1 = Zeeya | title = Collaborative physics: string theory finds a bench mate | journal = Nature | volume = 478 | pages = 302–304 | year = 2011 | doi = 10.1038/478302a | pmid = 22012369 | issue = 7369|bibcode = 2011Natur.478..302M | doi-access = free }} | |||