Structure and dynamics of spin polarons induced by doping a Haldane spin-1 chain Collin Broholm * Johns Hopkins University and NIST Center for Neutron.

Slides:

Advertisements

Similar presentations

Quasiparticle Scattering in 2-D Helical Liquid arXiv: X. Zhou, C. Fang, W.-F. Tsai, J. P. Hu.

Advertisements

Level Splitting in Frustrated non-Kramers doublet systems Collin Broholm and Joost van Duijn Department of Physics and Astronomy Johns Hopkins University.

Unveiling the quantum critical point of an Ising chain Shiyan Li Fudan University Workshop on “Heavy Fermions and Quantum Phase Transitions” November 2012,

Theory of the pairbreaking superconductor-metal transition in nanowires Talk online: sachdev.physics.harvard.edu Talk online: sachdev.physics.harvard.edu.

Spectroscopy at the Particle Threshold H. Lenske 1.

HL-3 May 2006Kernfysica: quarks, nucleonen en kernen1 Outline lecture (HL-3) Structure of nuclei NN potential exchange force Terra incognita in nuclear.

Ultrashort Lifetime Expansion for Resonant Inelastic X-ray Scattering Luuk Ament In collaboration with Jeroen van den Brink and Fiona Forte.

Exploring Quantum Magnetism through Neutron Scattering  What is Quantum Magnetism?  Where do we find it?  Why is it interesting?  Summary & Prospects.

Spin dynamics of stripe-ordered layered nickelates Andrew Boothroyd Department of Physics, Oxford University Ni 2+ (S=1) Ni 3+ (S=1/2) Cu 2+ (S=1/2) Cu.

Study of Collective Modes in Stripes by Means of RPA E. Kaneshita, M. Ichioka, K. Machida 1. Introduction 3. Collective excitations in stripes Stripes.

D-wave superconductivity induced by short-range antiferromagnetic correlations in the Kondo lattice systems Guang-Ming Zhang Dept. of Physics, Tsinghua.

Superconductivity in Zigzag CuO Chains

Magnetic Interactions and Order-out-of-disorder in Insulating Oxides Ora Entin-Wohlman, A. Brooks Harris, Taner Yildirim Robert J. Birgeneau, Marc A. Kastner,

Interplay between spin, charge, lattice and orbital degrees of freedom Lecture notes Les Houches June 2006 lecture 3 George Sawatzky.

Quantum effects in Magnetic Salts Part II G. Aeppli London Centre for Nanotechnology.

Spin Waves in Stripe Ordered Systems E. W. Carlson D. X. Yao D. K. Campbell.

DYNAMICAL PROPERTIES OF THE ANISOTROPIC TRIANGULAR QUANTUM

The attraction of  + to O 2- : using muons to study oxides Steve Blundell Clarendon Laboratory, Dept. Physics, University Of Oxford, UK.

Crystal Lattice Vibrations: Phonons

Ying Chen Los Alamos National Laboratory Collaborators: Wei Bao Los Alamos National Laboratory Emilio Lorenzo CNRS, Grenoble, France Yiming Qiu National.

Impurities and finite temperature effects in a one-dimensional spin-1 antiferromagnet Coherent excitations in Y 2 BaNiO 5 Loss of coherence for T>0 Chain-end.

Electron coherence in the presence of magnetic impurities

Dynamics Neutron Scattering and Dan Neumann

Neutron Scattering from Geometrically Frustrated Antiferromagnets Spins on corner-sharing tetrahedra Paramagnetic phase Long Range Ordered phase (ZnCr.

Charge transport in DNA molecules: Structural and dynamical disorder 张伟北京应用物理与计算研究所 2007 年 10 月.

Proposal for a High Intensity Chopper Spectrometer at LANSCE Science requiring high sensitivity neutron spectroscopy Limitations of current instrumentation.

Incommensurate correlations & mesoscopic spin resonance in YbRh 2 Si 2 * *Supported by U.S. DoE Basic Energy Sciences, Materials Sciences & Engineering.

Photo-induced ferromagnetism in bulk-Cd 0.95 Mn 0.05 Te via exciton Y. Hashimoto, H. Mino, T. Yamamuro, D. Kanbara, A T. Matsusue, B S. Takeyama Graduate.

Structure and dynamics of spin polarons induced by doping a Haldane spin-1 chain Collin Broholm * Johns Hopkins University and NIST Center for Neutron.

Magnetic Neutron Scattering Neutron spin meets electron spin Magnetic neutron diffraction Inelastic magnetic neutron scattering Polarized neutron scattering.

Neutron Scattering of Frustrated Antiferromagnets Satisfaction without LRO Paramagnetic phase Low Temperature phase Spin glass phase Long range order Spin.

Solving Impurity Structures Using Inelastic Neutron Scattering Quantum Magnetism - Pure systems - vacancies - bond impurities Conclusions Collin Broholm*

Neutron Scattering Studies of Tough Quantum Magnetism Problems

Finite Temperature Spin Correlations in Quantum Magnets with a Spin Gap Collin Broholm* Johns Hopkins University and NIST Center for Neutron Research *supported.

MACS Concept and Project Status Making best use of CW source MACS-imizing incident flux MACS-imizing detection efficiency From concept to reality Collin.

Anomalous two-neutron transfer in neutron-rich Ni and Sn isotopes studied with continuum QRPA H.Shimoyama, M.Matsuo Niigata University 1 Dynamics and Correlations.

Magnets without Direction Collin Broholm Johns Hopkins University and NIST Center for Neutron Research  Introduction  Moment Free Magnetism in one dimension.

The Helical Luttinger Liquid and the Edge of Quantum Spin Hall Systems

Introduction to Molecular Magnets Jason T. Haraldsen Advanced Solid State II 4/17/2007.

Impurities and finite temperature effects in a one-dimensional spin-1 antiferromagnet Coherent excitations in Y 2 BaNiO 5 Loss of coherence for T>0 Chain-end.

Magnets without Direction Collin Broholm Johns Hopkins University and NIST Center for Neutron Research  Introduction  Moment Free Magnetism in one dimension.

Collin Broholm Johns Hopkins University and NIST Center for Neutron Research Quantum Phase Transition in a Quasi-two-dimensional Frustrated Magnet M. A.

Quasi-1D antiferromagnets in a magnetic field a DMRG study Institute of Theoretical Physics University of Lausanne Switzerland G. Fath.

MACS –a New High Intensity Cold Neutron Spectrometer at NIST September 24, 2002Collin L. Broholm Timothy D. Pike 1 Scientific Program and Requirements.

Holes in a Quantum Spin Liquid Collin Broholm * Johns Hopkins University and NIST Center for Neutron Research Y 2-x Ca x BaNiO 5 *supported by NSF DMR

Conceptual design and performance of high throughput cold spectrometer : MACS Why MACS Layout and key elements Performance Data collection Scientific program.

Inhomogeneous Level Splitting in Pr x Bi 2-x Ru 2 O 7 Collin Broholm and Joost van Duijn Department of Physics and Astronomy Johns Hopkins University.

Magnetic Frustration at Triple-Axis  Magnetism, Neutron Scattering, Geometrical Frustration  ZnCr 2 O 4 : The Most Frustrated Magnet How are the fluctuating.

Holes in a Quantum Spin Liquid

Past and Future Insights from Neutron Scattering Collin Broholm * Johns Hopkins University and NIST Center for Neutron Research  Virtues and Limitations.

Superconductivity with T c up to 4.5 K 3d 6 3d 5 Crystal field splitting Low-spin state:

Collin Broholm * Johns Hopkins University and NIST Center for Neutron Research Y. ChenJHU, Baltimore, USA M. EnderleILL, Grenoble, France Z. HondaRiken,

Magnetized States of Quantum Spin Chains

Antiferromagnetic Resonances and Lattice & Electronic Anisotropy Effects in Detwinned La 2-x Sr x CuO 4 Crystals Crystals: Yoichi Ando & Seiki Komyia Adrian.

Collin Broholm Johns Hopkins University and NIST Center for Neutron Research Quantum Phase Transition in Quasi-two-dimensional Frustrated Magnet M. A.

Basics of edge channels in IQHE doing physics with integer edge channels studies of transport in FQHE regime deviations from the ‘accepted’ picture Moty.

Frustrated magnetism in 2D Collin Broholm Johns Hopkins University & NIST  Introduction Two types of antiferromagnets Experimental tools  Frustrated.

Excitations in an alternating spin-1/2 chain  Why study an alternating spin chain?  Excitations for T=0  Propagating triplet mode  Triplet pair excitations.

Neutron Scattering of Frustrated Antiferromagnets Satisfaction without LRO Paramagnetic phase Low Temperature phases Spin glass phase Long range order.

10/24/01PPHMF-IV1 Spinons, Solitons, and Breathers in Quasi-one-dimensional Magnets Frustrated Magnetism & Heavy Fermions Collin Broholm Johns Hopkins.

Magnets without Direction Collin Broholm Johns Hopkins University and NIST Center for Neutron Research  Introduction  Moment Free Magnetism in one dimension.

Holes in a Quantum Spin Liquid Collin Broholm * Johns Hopkins University and NIST Center for Neutron Research Y 2-x Ca x BaNiO 5 *supported by the NSF.

One Dimensional Magnetic Systems Strong Fluctuations in Condensed Matter Magnetism in one dimension Pure systems Doped systems Magnetized states Conclusions.

Collin Broholm Johns Hopkins University and NIST Center for Neutron Research Quantum Phase Transition in Quasi-two-dimensional Frustrated Magnet M. A.

Evolution of the orbital Peierls state with doping

Collin Broholm * Johns Hopkins University and NIST Center for Neutron Research Y. Chen LANL M. Kenzelmann JHU & NIST C. P. LandeeClarke University K. Lefmann.

Solving Impurity Structures Using Inelastic Neutron Scattering Quantum Magnetism - Pure systems - vacancies - bond impurities Conclusions Collin Broholm*

Production of an S(α,β) Covariance Matrix with a Monte Carlo-Generated

Magnetic and Raman response properties in La2CuO4

Kernfysica: quarks, nucleonen en kernen

Presentation transcript:

Structure and dynamics of spin polarons induced by doping a Haldane spin-1 chain Collin Broholm * Johns Hopkins University and NIST Center for Neutron Research * Supported by the National Science Foundation Ying Chen LANL Guangyong XuBNL G. AeppliUCL J. F. DiTusaLSU I. A. ZaliznyakBNL C. D. FrostISIS T. ItoTsukuba M. KenzelmannJHU K. Oka Tsukuba H. TakagiISSP M. E. Bisher NEC M. M. J. TreacyNEC R. PaulNIST Xu et al., Science 289, 419 (2000) Kenzelmann et al., PRL 90, (2003)

Outline  Introduction to neutrons and Y 2 BaNiO 5  On-chain non-magnetic doping  Off chain hole doping  Conclusions and outlook

APS 3/5/03 SPINS cold neutron spectrometer at NCNR kiki kfkf Q

APS 3/5/03 MAPS Spectrometer at ISIS in UK

APS 3/5/03 Haldane gap in Y 2 BaNiO 5 Ni 2+ Impure Pure Y 2 BaNiO 5 Nuclear Elastic Scattering

APS 3/5/03 Single mode approximation for spin-1 chain Dispersion relation Equal time correlation function Ma et al., PRL 69, 3571 (1992).

APS 3/5/03 Anisotropy and inter-chain coupling  intensity (coutns per 15 min.) I(q,w) (1/meV)  a  b  c Maintaining, we Derive polarization by rotating about chain Look for inter-chain coupling by varying Weak anisotropy: Highly one dimensional

APS 3/5/03 Facts on Y 2 BaNiO 5 Intra-chain exchange Anisotropy Dipole in field Inter-chain exchange

APS 3/5/03 Outline  Introduction to neutrons and Y 2 BaNiO 5  On-chain non-magnetic doping  Off chain hole doping  Conclusions and outlook

APS 3/5/03 Impurities in Y 2 BaNiO 5 Ca 2+ Y 3+ Mg 2+ on Ni 2+ sites Site centered defects Ca 2+ on Y 3+ sites bond centered defects Mg Ni Kojima et al. (1995) Mg Pure

APS 3/5/03 An ensemble of finite length chains Chain length L P(L) 2% 4% 8% P(  )/ max (P(  )) 2% 4% 8% Probability spin in segment of length L Gap from chain of length L Ensemble averaged scattering

APS 3/5/03 Haldane gap with impurities Kenzelmann et al. PRL (2003)

APS 3/5/03 How about chain ends? L is even L is odd Singlet-triplet Single ion anisotropy Zeeman

APS 3/5/03 Chain-end composite spin

APS 3/5/03 Form factor for chain-end spin Kenzelmann et al. PRL (2003)

APS 3/5/03 Outline  Introduction to neutrons and Y 2 BaNiO 5  On-chain non-magnetic doping  Off chain hole doping  Conclusions and outlook

APS 3/5/03 Transport in Ca doped Y 2 BaNiO 5 T. Ito et al. Submitted to PRL (2001) Charge Transfer excitation Charge polaron 1D conductivity, no Charge ordering

APS 3/5/03 Impurities in Y 2 BaNiO 5 Ca 2+ Y 3+ Mg Ni Kojima et al. (1995) Mg Ca 2+ Pure Mg 2+ on Ni 2+ sites Site centered defects Ca 2+ on Y 3+ sites bond centered defects

APS 3/5/03 Gap modes in 4% Ca-doped Y 2 BaNiO 5

APS 3/5/03 Why is Y 2-x Ca x BaNiO 5 incommensurate?  Charge ordering yields incommensurate spin order  Quasi-particle Quasi-hole pair excitations in Luttinger liquid  Single impurity effect x q   q indep. of x

APS 3/5/03 Does  q vary with calcium concentration?  q not strongly dependent on x single impurity effect Xu et al., Science 289, 419 (2000)

APS 3/5/03 Bond Impurities in a spin-1 chain: Y 2-x Ca x BaNiO 5 Y3+Y3+ Ni O AFMFM Ca 2+

Form-factor for FM-coupled chain-end spins A symmetric AFM droplet Ensemble of independent randomly truncated AFM droplets

APS 3/5/03 Gap modes in 4% Ca-doped Y 2 BaNiO 5 Excited state Quasi-elastic From deg. GS Quasi-elastic From deg. GS

APS 3/5/03 Dynamic model of spin polaron

APS 3/5/03 Intra polaron dynamics in Ca-doped Y 2 BaNiO Normalized Intensity (Arb) Pure 4% Ca Intra quartet Clean gap ?

APS 3/5/03 Conclusions:  Dilute impurities in the Haldane spin chain create sub-gap composite spin degrees of freedom.  Edge states have an AFM wave function that extends into the bulk over distances of order the Haldane length.  Ca doping yields charge polarons with 1 eV binding energy  Holes in Y 2-x Ca x BaNiO 5 are surrounded by AFM spin polaron with central phase shift of   Spin polaron spectrum described as three interacting spins-1/2 with J FM = 9 meV Viewgraphs and publications at

APS 3/5/03 Outlook  Confirm level assignment in field  What is localization length for spin polaron?  Spin polaron structure in frustrated magnets  Spin polarons in high T C superconductors?  Magnetism of interacting spin polarons Design by T. D. Pike