Dynamic spin response for Heisenberg ladders
| Autor: | Jorge Piekarewicz, J. R. Shepard |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
Physics
Strongly Correlated Electrons (cond-mat.str-el) Nuclear Theory Basis (linear algebra) Heisenberg model Truncation Isotropy FOS: Physical sciences Nuclear Theory (nucl-th) Renormalization Many-body problem Condensed Matter - Strongly Correlated Electrons Quantum mechanics Condensed Matter::Strongly Correlated Electrons Energy (signal processing) Spin-½ |
| Zdroj: | Physical Review B. 57:10260-10263 |
| ISSN: | 1095-3795 0163-1829 |
| Popis: | We employ the recently proposed plaquette basis to investigate static and dynamic properties of isotropic 2-leg Heisenberg spin ladders. Simple non-interacting multi-plaquette states provide a remarkably accurate picture of the energy/site and dynamic spin response of these systems. Insights afforded by this simple picture suggest a very efficient truncation scheme for more precise calculations. When the small truncation errors are accounted for using recently developed Contractor Renormalization techniques, very accurate results requiring a small fraction of the computational effort of exact calculations are obtained. These methods allow us to determine the energy/site, gap, and spin response of 2x16 ladders. The former two values are in good agreement with density matrix renormalization group results. The spin response calculations show that nearly all the strength is concentrated in the lowest triplet level and that coherent many-body effects enhance the response/site by nearly a factor of 1.6 over that found for 2x2 systems. 9 pages with two enclosed postscript figures |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|