Stripe Ordering in the CupratesWhat is Stripe Ordering?Why does Stripe Ordering Occur?The Distance that Separates.Scattering Basics (Preclude to testing for stripe ordering.)Magnetic ScatteringReciprocal Space of CuO4 in the Presence of Stripe Ordering.Estimate of δ as a function of x.Neutron ScatteringWhat Proof do We have of Stripe Ordering?What does Stripe Ordering Mean for Superconductivity?ReferencesStripe Ordering in the CupratesLeland HarrigerHomework Project for Solid State IIInstructor: Elbio DagottoPhysics Dept., University of Tennessee at KnoxvilleSpring 2009What is Stripe Ordering?A periodic modulation of charge and spin.Modulation of charge and spin are related by the phase boundary.Result: Spin periodicity is twice that of charge periodicityWhy does Stripe Ordering Occur?The Distance that Separates.)(1)(copperholesxnh)()(1copperNholenhaLN2xaLc2xaLm42CuOSrLaxxScattering Basics (Preclude to testing for stripe ordering.)ifkkQ Magnetic Scattering0L2222cLbKaHQKH ba dQ2)0,,( HHQ 21HReciprocal Space of CuO4 in the Presence of Stripe Ordering.Big Circles are nuclear Bragg peaks.Small plusses are magnetic Bragg peaks.Other symbols are incommensurate spreading of peaks due to stripe ordering.Estimate of δ as a function of x.xaLc2xaLmxc~2cmNeutron ScatteringThe triple axis spectrometer is very versatile for measurements of bulk solids.Q-scans (ie: momentum transfer)Both elastic and inelasticTypically performed at a fixed energy transfer.Energy ScansSet E=0 for elastic scansTypically performed at a fixed Q.What Proof do We have of Stripe Ordering?What does Stripe Ordering Mean for Superconductivity?References[1] J. Orenstein, et. al Science 288, 468 (2000)J. Tranquada, et. al. Nature 375, 561J. Tranquada, et. al. Phys. Rev. Lett. 78, 338S. Chi, et. al. Phys. Rev. Lett. 102 107005Ph. Bourges, et. al. Physica C 424, 45Yamada K. et. al. Phys. Rev. B 57
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