Spinon confinement in a quasi-one-dimensional anisotropic Heisenberg magnet
| Autor: | Astrid Schneidewind, Laurens Vanderstraeten, Fabian H. L. Essler, Claudius Hubig, A. T. M. N. Islam, Ulrich Schollwöck, D. L. Quintero-Castro, Anup Kumar Bera, Bella Lake |
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| Rok vydání: | 2018 |
| Předmět: |
Quark
QUANTUM CRITICALITY FOS: Physical sciences 02 engineering and technology 01 natural sciences Resonance (particle physics) CONDENSATION Condensed Matter - Strongly Correlated Electrons 0103 physical sciences Bound state ddc:530 CHAINS 010306 general physics spinon confinement anisotropic Heisenberg ANTIFERROMAGNETS Spin-½ Physics EXCITATION CONTINUUM Condensed matter physics Strongly Correlated Electrons (cond-mat.str-el) 021001 nanoscience & nanotechnology Quantum number Spin quantum number Spinon FIELD-THEORY MODEL Physics and Astronomy Quasiparticle Condensed Matter::Strongly Correlated Electrons 0210 nano-technology |
| Zdroj: | Physical review / B 96(5), 054423 (2017). doi:10.1103/PhysRevB.96.054423 PHYSICAL REVIEW B |
| ISSN: | 2469-9950 2469-9969 |
| DOI: | 10.1103/physrevb.96.054423 |
| Popis: | Confinement is a process by which particles with fractional quantum numbers bind together to form quasiparticles with integer quantum numbers. The constituent particles are confined by an attractive interaction whose strength increases with increasing particle separation and as a consequence, individual particles are not found in isolation. This phenomenon is well known in particle physics where quarks are confined in baryons and mesons. An analogous phenomenon occurs in certain magnetic insulators; weakly coupled chains of spins S=1/2. The collective excitations in these systems is spinons (S=1/2). At low temperatures weak coupling between chains can induce an attractive interaction between pairs of spinons that increases with their separation and thus leads to confinement. In this paper, we employ inelastic neutron scattering to investigate the spinon confinement in the quasi-1D S=1/2 XXZ antiferromagnet SrCo2V2O8. Spinon excitations are observed above TN in quantitative agreement with established theory. Below TN the pairs of spinons are confined and two sequences of meson-like bound states with longitudinal and transverse polarizations are observed. Several theoretical approaches are used to explain the data. A new theoretical technique based on Tangent-space Matrix Product States gives a very complete description of the data and provides good agreement not only with the energies of the bound modes but also with their intensities. We also successfully explained the effect of temperature on the excitations including the experimentally observed thermally induced resonance between longitudinal modes below TN ,and the transitions between thermally excited spinon states above TN. In summary, our work establishes SrCo2V2O8 as a beautiful paradigm for spinon confinement in a quasi-1D quantum magnet and provides a comprehensive picture of this process. Comment: 17 pages, 18 figures, submitted to PRX |
| Databáze: | OpenAIRE |
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