Anisotropic London Theory is used to predict the Abriskosv flux lattice in planar crystals of YBaCuO. By taking into account the orientation of the flux lattice as a function of applied field it is shown that the vortex chain state is observed in Bitter pa

TheAbrikosovFluxLatticeinPlanarCrystalsofYBa2Cu3O7 δ

M.HarrisonandW.Barford

DepartmentofPhysics,TheUniversityofShe eld,

She eld,S37RH,UnitedKingdom.

(February1,2008)

arXiv:cond-mat/9407002v1 1 Jul 1994AbstractAnisotropicLondontheoryisusedtopredicttheAbrikosov uxlatticeforarbitrary eldorientationsincrystalsofYBa2Cu3O7 δbyminimisingtheGibbsfreeenergyforsamplesofaplanargeometry.Atlow eldsthe“vortex-chain”stateexists,i.e.theinter-chainvortexseparationscalesastheinverse uxdensity,1/B,whereastheintra-chainvortexseparationisconstant.Athigher eldsthereisacross-overtotheuniaxiallydistortedhexagonallatticewheretheinter-vortexseparationscalesas1/B1/2.Atlow eldsthevortexlatticeisinclinedtowardsthe caxis,rotatingtowardstheapplied eldathigher elds.Theresultsofthiscalculationareincloseagreementtothe

BitterpatternexperimentsofGammeletal.1assummingananisotropyratio

γof5andanin-planepenetrationdepthλaof1413 A,indicatingthatthe

“vortex-chain”statehasbeenobservedintheseexperiments.

PACSNumbers:74.60.Ec,61.16.Bg,74.72.Bk

*Towhomcorrespondenceshouldbeaddressed.