Phase transition in non-equilibrium thermo field dynamics

I. Hardman*, H. Umezawa, Y. Yamanaka

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


The phase transition between ordered and disordered states is discussed within the framework of non-equilibrium Thermo Field Dynamics (TFD), in which the time-dependent thermal Bogoliubov transformation takes care of the temporal change of quasi-particles. Thus, the system, which is closed, passes through a continuum of out of equilibrium states in going from one phase to another. The formalism is presented for the superfluid model. The time evolution of the system is determined by the self-consistent renormalization conditions which give us equations for the order parameter, number distributions, dissipative coefficients and renormalized energies. A differential Ward-Takahashi relation, rather than an integral one, is combined with the renormalization condition to study the zero momentum mode.

Original languageEnglish
Pages (from-to)326-335
Number of pages10
JournalPhysica A: Statistical Mechanics and its Applications
Issue number1
Publication statusPublished - 1989 May 15
Externally publishedYes

ASJC Scopus subject areas

  • Statistics and Probability
  • Condensed Matter Physics


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