Many-bodyab initiostudy of antiferromagnetic{Cr7M}molecular rings
| Autor: | Stefano Carretta, Paolo Santini, Eva Pavarini, Giuseppe Amoretti, Alessandro Chiesa |
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| Rok vydání: | 2016 |
| Předmět: |
Physics
Condensed matter physics Field (physics) Isotropy Ab initio Spin hamiltonian 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Many body Scheme (mathematics) 0103 physical sciences Antiferromagnetism Condensed Matter::Strongly Correlated Electrons 010306 general physics 0210 nano-technology Anisotropy |
| Zdroj: | Physical Review B. 94 |
| ISSN: | 2469-9969 2469-9950 |
| DOI: | 10.1103/physrevb.94.224422 |
| Popis: | Antiferromagnetic molecular rings are widely studied both for fundamental quantum-mechanical issues and for technological applications, particularly in the field of quantum information processing. Here we present a detailed first-principles study of two families---purple and green---of ${{\mathrm{Cr}}_{7}M}$ antiferromagnetic rings, where $M$ is a divalent transition metal ion ($M={\mathrm{Ni}}^{2+}, {\mathrm{Mn}}^{2+}$, and ${\mathrm{Zn}}^{2+}$). We employ a recently developed flexible and efficient scheme to build ab initio system-specific Hubbard models. From such many-body models we systematically derive the low-energy effective spin Hamiltonian for the rings. Our approach allows us to calculate isotropic as well as anisotropic terms of the spin Hamiltonian, without any a priori assumption on its form. For each compound we calculate magnetic exchange couplings, zero-field splitting tensors, and gyromagnetic tensors, finding good agreement with experimental results. |
| Databáze: | OpenAIRE |
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