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Low‐temperature renormalization group and symmetry breaking perturbations
Author(s) -
Nattermann Th.
Publication year - 1978
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2220900111
Subject(s) - gravitational singularity , renormalization group , symmetry breaking , physics , spontaneous symmetry breaking , mathematical physics , perturbation (astronomy) , global symmetry , quantum mechanics
A skeleton graph approach in d = 2 + ϵ dimensions is used to calculate the low‐temperature properties of a n ‐component classical Heisenberg model. The approach allows a unified description of both Goldstone and critical singularities. The influence of small symmetry breaking fields on these singularities is investigated. The main results are closed form expressions for the correlation functions, the equation of state, and the free energy. If n ≧ 3 these fields are stongly relevant. In particular, a small cubic perturbation leads to a first‐order transition. For n = 2 perturbations with the symmetry of a p ‐fold axis may become irrelevant for a certain temperature region.