Intended for graduates in physics and related fields, this is a self-contained treatment of the physics of many-body systems from the point of view of condensed matter. The approach, quite traditionally, covers all the important diagram techniques for normal and superconducting systems, including the zero-temperature perturbation theory, and the Matsubara, Keldysh, and Nambu-Gorov formalisms. The aim is not to be exhaustive, but to present just enough detail to enable students to follow the current research literature or to apply the techniques to new problems. Many of the examples are drawn from mesoscopic physics, which deals with systems small enough that quantum coherence is maintained throughout the volume, and which therefore provides an ideal testing ground for many-body theories. '
Intended for graduate students in physics and related fields, this text
is a self contained treatment of the physics of many-body systems from
the point of view of condensed matter. The approach, quite traditionally,
uses the mathematical formalism of quasiparticles and Green's functions.
In particular, it covers all the important diagram techniques for normal
and superconducting systems, including the zero- temperature perturbation
theory, and the Matsubara, Keldysh, and Nambu -Gor'kov formalisms. The
aim is not to be exhaustive, but to present just enough detail to enable
the student to follow the current research literature or to apply the techniques
to new problems. Many of the examples are drawn from mesoscopic physics,
which deals with systems small enough that quantum coherence is maintained
throughout their volume, and which therefore provides an ideal testing
ground for many-body theories. The book begins by introducing the Green's
function for one-particle systems (using Feynman path integrals), general
perturbation theory, and second quantization. It then turns to the usual
zero-temperature formalism, discussing the properties and physical meaning
of the Green's function for many-body systems and then developing the diagram
techniques of perturbation theory. The theory is extended to finite temperatures,
including a discussion of the Matsubara formalism as well as the Keldysh
technique for essentially nonequilibrium systems. The final chapter is
devoted to applications of the techniques to superconductivity, incuding
discussions of the superconducting phase transition, elementary excitations,
transport, Andreev reflections, and Josephson junctions. Problems at the
end of each chapter help to guide learning an to
