Interaction of a conduction electron with critical fluctuations of the spin density in the s-d exchange model of a magnetic semiconductor. Estimate of the free energy and static conductivity Academic Article uri icon

abstract

  • By means of Feynman path integrals and the variational principle estimates are obtained for the free energy of the bound state of a conduction electron with critical fluctuations of the spin density when T~ T c (flucton). A condition under which the fluctuations can be regarded as Gaussian is found. A study is made of the case of Kac's model for a spin subsystem, and the connection between the proposed quantum-statistical approach and the phenomenological theory is established. In the Gaussian case, an expression is obtained …

publication date

  • May 1, 1980