Aim. The aim of the paper is to study the impact of the works of R. Feynman and J. Schwinger on the development of condensed matter physics in the Soviet Union in the end 1940s and early 1960s. Method. The research is based on the analysis of original works with the use of available literature concerning the issue under consideration. Results. The transfer of the methods of quantum field theory to the many-body problem was a very complex and nontrivial task. The main contribution to its solution was made by physicists from the environment of L.D. Landau.