Anisotropic Heinsenberg interface between Ising bulk ferromagnets: a renormalization group approach
- 1. Alagoas Univ., Maceio (Brazil). Dept. de Fisica
- 2. Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro
Description
Two semi-infinite spin 1/2 Ising media are considered (respectively characterized by the ferromagnetic coupling constants J1 and J2) separated by a spin 1/2 anisotropic Heisenberg interface (characterized by a ferromagnetic coupling constant J sub(S), and by a anisotropy eta epsilon [0, 1] in spin space; eta=1 and eta=0 respectively correspond to the Ising and isotropic Heisenberg limits). Within a real-space renormalization-group framework, the full phase diagram is discussed, this diagram exhibits, besides the paramagnetic phase, three physically different ordered phases, namely the double-bulk, single-bulk and surface ferromagnetic ones. The various universality classes appearing in this problem are also analized, and, in particular, the existence of a new high-order multicritical point associated with the J1 = J2 case is determined. (Author)
Availability note (English)
MF available from INIS under the Report Number.Abstract (Portuguese)
Consideram-se dois meios de Ising de spin 1/2 semi-infinito (caracterizados respectivamente pelas constantes de acoplamento ferromagneticas J1 e J2) separados por uma interface de Heisenberg anisotropica de spin 1/2 (caracterizada por uma constante de acoplamento ferromagnetica J sub(S), e por uma anisotropia eta epsilon [0, 1] no espaco de spin, eta=1 e eta=0 corresponde respectivamente aos limites de Ising e de Heisenberg isotropico). Discute-se, dentro de uma estrutura de grupo de renormalizacao de espaco real, o diagrama de fase completo; esse diagrama exibe, alem da fase paramagnetica, tres fases ordenadas fisicamente diferentes, a saber a fase de volume duplo, a fase de volume simples e a fase ferromagnetica de superficie. Analizam-se tambem as varias classes de universalidade que aparecem nesse problema e determina-se, em particular, a existencia de um novo ponto multicritico de alta ordem associado com o caso J1 = J2. (L.C.)Files
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Additional details
Publishing Information
- Imprint Pagination
- 21 p.
- Report number
- CBPF-NF--028/85
INIS
- Country of Publication
- Brazil
- Country of Input or Organization
- Brazil
- INIS RN
- 17010839
- Subject category
- S75: CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY;
- Resource subtype / Literary indicator
- Numerical Data
- Descriptors DEI
- ANISOTROPY; CRYSTAL MODELS; CUBIC LATTICES; GROUP THEORY; MAGNETISM; PHASE DIAGRAMS; RENORMALIZATION; SPIN; SURFACES; THEORETICAL DATA
- Descriptors DEC
- ANGULAR MOMENTUM; CRYSTAL LATTICES; CRYSTAL STRUCTURE; DATA; DIAGRAMS; INFORMATION; MATHEMATICAL MODELS; MATHEMATICS; NUMERICAL DATA; PARTICLE PROPERTIES