Statistical-mechanical theory of electron gas on the basis of Feynman path integrals

Continual-integral method proposed by Feyman provides a quantum-statistical method with allowance for exchange effects and thermal fluctuations to explain the propertied of electron gas. The formulation of quantum mechanics in terms of Feynman path integrals has allowed to construct method free of the single-electron approximation and those of the average-field theory. The presence of diagrams with negative contributions complicates the stochastic calculation of the Feynman integrals, because the mutual compensation of the positive and negative contributions results in a depletion of the statistics accumulated and a rise in the statistical error. The quantum spatial delocalization of electrons leas to the weakening of spatial correlations. The pairing of electron-spin states results in the weakening of both the exchange repulsion and associated spatial correlations.