Starting from first principles, this book introduces the closely related phenomena of Bose condensation and Cooper pairing, in which a very large number of single particles or pairs of particles are forced to behave in exactly the same way, and explores their consequences in condensed matter systems. Eschewing advanced formal methods, the author uses simple concepts and arguments to account for the various qualitatively new phenomena which occur in Bose-condensed and Cooper-paired systems, including but not limited to the spectacular macroscopic phenomena of superconductivity and superfluidity. The physical systems discussed include liquid 4-He, the BEC alkali gases, "classical" superconductors, superfluid 3-He, "exotic" superconductors and the recently stabilized Fermi alkali gases. The book should be accessible to beginning graduate students in physics or advanced undergraduates.

Originally published as two separate volumes, The Theory of Quantum Liquids is a classic text that attempts to describe the qualitative and unifying aspects of an extremely broad and diversified field. Volume I deals with ‘normal’ Fremi liquids, such as 3He and electrons in metals. Volume II consists of a detailed treatment of Bose condensation and liquid 4He, including the development of a Bose liquid theory and a microscopic basis for the two-fluid model, and the description of the elementary excitations of liquid HeII.

Modern electronic devices and novel materials often derive their extraordinary properties from the intriguing, complex behavior of large numbers of electrons forming what is known as an electron liquid. This book provides an in-depth introduction to the physics of the interacting electron liquid in a broad variety of systems, including metals, semiconductors, artificial nano-structures, atoms and molecules. One, two and three dimensional systems are treated separately and in parallel. Different phases of the electron liquid, from the Landau Fermi liquid to the Wigner crystal, from the Luttinger liquid to the quantum Hall liquid are extensively discussed. Both static and time-dependent density functional theory are presented in detail. Although the emphasis is on the development of the basic physical ideas and on a critical discussion of the most useful approximations, the formal derivation of the results is highly detailed and based on the simplest, most direct methods.

This book is concerned with a single group of quantum liquids, normal Fermi liqztids, discussing the nature of elementary excitations, the central concept of response functions. It is intended as a text for a graduate course in quantum statistical mechanics or low temperature theory.

This book provides a unified account of the theory of quantum liquid and discusses the mathematical theory of linear response and correlations. It is helpful for experimental physicists working in the fields of low-temperature or solid-state physics.

This thesis presents an exact theoretical study of dynamical correlation functions in different phases of a two-dimensional quantum spin liquid. By calculating the dynamical spin structure factor and the Raman scattering cross section, this thesis shows that there are salient signatures—qualitative and quantitative—of the Majorana fermions and the gauge fluxes emerging as effective degrees of freedom in the exactly solvable Kitaev honeycomb lattice model. The model is a representative of a class of spin liquids with Majorana fermions coupled to Z2 gauge fields. The qualitative features of the response functions should therefore be characteristic for this broad class of topological states.

This book is concerned with a single group of quantum liquids, normal Fermi liqztids, discussing the nature of elementary excitations, the central concept of response functions. It is intended as a text for a graduate course in quantum statistical mechanics or low temperature theory.