holographic charge density waves(ppt)(20101015104057262[1])

《holographic charge density waves(ppt)(20101015104057262[1])》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。

1、HolographicChargeDensityWavesLefterisPapantonopoulosNationalTechnicalUniversityofAthensIncollaborationwithKITPCA.Aperis,P.Kotetes,GVarelogannisAllyouwanttoKnowaboutAdS/CFTG.SiopsisandP.SkamagoulisOct-Dec2010Firstresultsappearedin1009.6179zeroPlanofthetalk•DensityWaves•HolographicSuperc

2、onductors•HolographicChargeDensityWaves•ConclusionsDensityWavesFröhlich“principle”forsuperconductivity:Thecrystalicsystemsshapetheirspacing(lattice)toservetheneedsofconductivityelectronsThesimplerperhapsexample:PeierlsPhaseTransition•Ina1-Dlattice,themetalsystemofions–electronsinthefun

3、damentallevelisunstableinlowtemperatures•Itreturnstoanewstateoflowerenergyviaaphasetransition•InthenewphasetheionsareshiftedtonewplacesandthedensityofelectronicchargeisshapedperiodicallyinthespaceADensityWave,isanypossiblekindoforderedstatethatischaracterizedbyamodulatedmacroscopicphys

4、icalquantity.Considercorrelationsoftheform:generatetwogeneraltypesofdensitywaves:I.Densitywavesintheparticle-holechannelBoundstate:II.Densitywavesintheparticle-particlechannelBoundstate:q:momentumofthepairk:relativemomentumf(k)denotestheirreduciblerepresentationa,b,..->Spin,Isospin,Fla

5、vour,etc•Densitywaves(p-h)Neutralparticle-holepairelectromagneticU(1)symmetryispreserved•PairDensitywaves(p-p)Charged2eparticle-particlepairelectromagneticU(1)symmetryisspontaneouslybrokenBothkindsofDensitywavesaredistinguishedin:Commensurate:whentheorderingwave-vectorcanbeembeddedto

6、theunderlyinglatticeTranslationalsymmetryisdowngradedIncommensurate:whentheorderingwave-vectorcannotberelatedtoanywave-vectorofthereciprocallatticeU(1)Translationalsymmetryisspontaneouslybroken1D-ChargeDensityWavesMinimizationoftheenergy:Openingofagapatkf,-kf.Originoftheinteraction:

7、Electron-phononPeierlstransitionwithalatticedistortion.Electron-electroneffectiveinteractionnotcoupledtothelatticeG.GruenerRev.Mod.Phys.60,1129(1988)Rev.Mod.Phys.66,1(1994)CollectivephenomenaindensitywavesDDDDInincommensuratedensitywavesU(1)translationalsymmetryisbrokenAppearanceo