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Symmetric‐group algebraic variational solutions for Heisenberg models at finite temperature
Author(s) -
Klein D. J.,
Seitz W. A.
Publication year - 1992
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.560410107
Subject(s) - hamiltonian (control theory) , algebraic number , heisenberg group , group (periodic table) , mathematics , mathematical physics , heisenberg model , algebra over a field , quantum mechanics , physics , pure mathematics , mathematical analysis , mathematical optimization , ferromagnetism
The Heisenberg spin Hamiltonian for a collection of N spin‐1/2 sites is viewed, as favored by Professor Matsen, to be an element of the group algebra of the symmetric group N . Several computationally tractable, variational group–algebraic approximations for the finite‐temperature density matrix are made so as to minimize the Gibb's free–energy functional. Relations to previous quite differently motivated approximations are identified, though improvements are noted with the present approach.