DOI: https://doi.org/10.30970/jps.03.312
FREE FERMIONS IN TWO-DIMENSIONAL ISING MODEL
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Journal of Physical Studies 3(3), 312–330 (1999)
DOI: https://doi.org/10.30970/jps.03.312 FREE FERMIONS IN TWO-DIMENSIONAL ISING MODEL |
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V. N. Plechko
Bogoliubov Laboratory of Theoretical Physics,
Joint Institute for Nuclear Research,
141980, Dubna, Moscow Region, Russia
The two–dimensional (2D) Ising model is reviewed as a theory of free fermions on a lattice. The discussion includes the fermionization procedure based on the mirror–ordered factorization of the density matrix, Gaussian fermionic integral representation for partition function, the momentum–space analysis and Onsager's result, the effective continuum–limit field theories and the critical–point singularities. The emergence of long–range fermionic correlations in a nonzero magnetic field and the behaviour of the specific heat along the critical isotherm are commented. Attention is given to the choice of rational computational devices.