This book focuses on the topological fermion condensation quantum phase transition (FCQPT), a phenomenon that reveals the complex behavior of all strongly correlated Fermi systems, such as heavy fermion metals, quantum spin liquids, quasicrystals, and two-dimensional systems, considering these as a new state of matter. The book combines theoretical evaluations with arguments based on experimental grounds demonstrating that the entirety of very different strongly correlated Fermi systems demonstrates a universal behavior induced by FCQPT. In contrast to the conventional quantum phase transition, whose physics in the quantum critical region are dominated by thermal or quantum fluctuations and characterized by the absence of quasiparticles, the physics of a Fermi system near FCQPT are controlled by a system of quasiparticles resembling the Landau quasiparticles. The book discusses the modification of strongly correlated systems under the action of FCQPT, representing the “missing” instability, which paves the way for developing an entirely new approach to condensed matter theory; and presents this physics as a new method for studying many-body objects. Based on the authors’ own theoretical investigations, as well as salient theoretical and experimental studies conducted by others, the book is well suited for both students and researchers in the field of condensed matter physics.

The physics of strongly correlated fermions and bosons in a disordered envi ronment and confined geometries is at the focus of intense experimental and theoretical research efforts. Advances in material technology and in low temper ature techniques during the last few years led to the discoveries of new physical of atomic gases and a possible metal phenomena including Bose condensation insulator transition in two-dimensional high mobility electron structures. Situ ations were the electronic system is so dominated by interactions that the old concepts of a Fermi liquid do not necessarily make a good starting point are now routinely achieved. This is particularly true in the theory of low dimensional systems such as carbon nanotubes, or in two dimensional electron gases in high mobility devices where the electrons can form a variety of new structures. In many of these sys tems disorder is an unavoidable complication and lead to a host of rich physical phenomena. This has pushed the forefront of fundamental research in condensed matter towards the edge where the interplay between many-body correlations and quantum interference enhanced by disorder has become the key to the understand ing of novel phenomena.

Detailed account of important technique for researchers and graduate students working in condensed matter and theoretical physics.

Since the discovery of high Tc superconductivity, the role of electron correlation on superconductivity has been an important issue in condensed matter physics. Here the role of electron correlation in metals is explained in detail on the basis of the Fermi liquid theory. The book, originally published in 2004, discusses the following issues: enhancements of electronic specific heat and magnetic susceptibility, effects of electron correlation on transport phenomena such as electric resistivity and Hall coefficient, magnetism, Mott transition and unconventional superconductivity. These originate commonly from the Coulomb repulsion between electrons. In particular, superconductivity in strongly correlated electron systems is discussed with a unified point of view. This book is written to explain interesting physics in metals for undergraduate and graduate students and researchers in condensed matter physics.

Focusing on the purely theoretical aspects of strongly correlated electrons, this volume brings together a variety of approaches to models of the Hubbard type - i.e., problems where both localized and delocalized elements are present in low dimensions. The chapters are arranged in three parts. The first part deals with two of the most widely used numerical methods in strongly correlated electrons, the density matrix renormalization group and the quantum Monte Carlo method. The second part covers Lagrangian, Functional Integral, Renormalization Group, Conformal, and Bosonization methods that can be applied to one-dimensional or weakly coupled chains. The third part considers functional derivatives, mean-field, self-consistent methods, slave-bosons, and extensions.

This volume presents a collection of review papers on recent work in the connected areas of strongly correlated systems, the effects of coherence on macroscopic systems, and entanglement in quantum systems. These areas have attracted considerable interest due to their complexity and associated unexpected nontrivial phenomena, and also due to their potential applications in various fields, from materials science to information technology. The coverage includes strongly correlated electronic systems such as low-dimensional complex materials, ordered and disordered spin systems, and aspects of the physics of manganites and graphene, both in equilibrium and far from equilibrium.