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1 个结果
  • 简介:WehavecomprehensivelyinvestigatedthefrustratedJ1-J2-J3Heisenbergmodelonasimplecubiclattice.Thismodelallowsthreeregimesofmagneticorder,viz.,(π;π;π),(0;π;π)and(0;0;π),denotedasAF1,AF2,andAF3,respectively.Theeffectsoftheinterplayofneighboringcouplingsonthemodelarestudiedintheentiretemperaturerange.Thezerotemperaturemagneticpropertiesofthismodelarediscussedutilizingthelinearspinwave(LSW)theory,nonlinearspinwave(NLSW)theory,andGreen’sfunction(GF)method.ThezerotemperaturephasediagramsevaluatedbytheLSWandNLSWmethodsareillustrated,andareobservedtoexhibitdifferentparameterboundaries.Incertainregionsandalongtheparameterboundaries,thepossiblephasetransformationsdrivenbytheparametersarediscussed.TheresultsobtainedusingtheLSW,NLSW,andGFmethodsarecomparedwiththoseobtainedusingtheseriesexpansion(SE)method,andareobservedtobeingoodagreementwhenthevalueofJ2isnotclosetotheparameterboundaries.ThegroundstateenergiesobtainedusingtheLSWandNLSWmethodsareclosetothatobtainedusingtheSEmethod.Atfinitetemperatures,onlytheGFmethodisemployedtoevaluatethemagneticproperties,andthecalculatedphasediagramisobservedtobeidenticaltotheclassicalphasediagram.Theresultsindicatethatattheparameterboundaries,atemperature-drivenfirst-orderphasetransitionbetweenAF1andAF2mayoccuralongtheboundaryline.AlongtheAF1-AF3andAF2-AF3boundarylines,AF3islessstablethanAF1andAF2.OurcalculatedcriticaltemperatureagreeswiththatobtainedusingMonteCarlosimulationsandpseudofermionfunctionalrenormalizationgroupscheme.

  • 标签: QUANTIZED SPIN models quantum phase TRANSITIONS