Volume 2 of the Quantum Mechanics textbook builds on the general foundations of the quantum theory explained in volume 1, focusing on more advanced areas of the quantum theory which are important for the study of atomic systems. The approximate solution for stationary problems by the variation and perturbation methods is uniformly derived through the use of projections. It discusses the importance of perturbation methods for time-independent perturbations. The perturbation solution of the non-stationary Schrödinger equation is derived from the Golden Rule, via Wigner-Weisskopf approximation for the general theory of states with exponential decay. The main focus of the text is presented in chapters on atomic systems as many-body problems: two-electron systems (atom of Helium, H2 molecule), Fano resonance, Hartree-Fock Theory, electron structure of atoms, and the basics of quantum chemistry. For large systems, e-e correlation, jellium as a model system, the theory and practice of the density functional theory, introduction to the methods of reduced density-matrix functionals and Green’s functions. The closing part of the book contains the theory of (elastic) dissipation and an extensive explanation of the semi-classical and quantum descriptions of the radiation-matter interaction, including Kubo formula and non-relativistic calculation of the Lamb shift.
The text includes many examples and analyses of a number of experimental solutions in the light of the presented theory.