Electronic Phase Separation in Magnetic and Superconducting Materials Recent Advances

This book focuses on nanoscale electronic phase separation in a wide class of different materials, especially in strongly correlated electron systems. It features an extensive review of the field of inhomogeneous spin and charge states in condensed matter physics while delivering a topical and timely discussion of a wide range of recent advances in electronic phase separation. It describes the formation of different types of nanoscale ferromagnetic metallic droplets in antiferromagnetically ordered, charge-ordered, or orbitally-ordered insulating matrices, as well as the colossal magnetoresistance effect and tunneling electron transport in the nonmetallic phase-separated state of complex magnetic oxides. It also discusses compounds with spin-state transitions, inhomogeneously phase-separated states in strongly correlated multiband systems, and the electron polaron effect, paying special attention to systems with imperfect Fermi surface-nesting such as chromium alloys, iron-based pnictides, and AA-stacked graphene bilayers. The authors investigate also the formation of order parameter clusters and insulator-superconductor transition in different superconducting systems including bismuth oxides, two-dimensional films in the presence of strong disorder, as well as inhomogeneous Fermi-Bose mixtures in Aharonov-Bohm rings with a superconducting bridge in a topologically nontrivial state. This book is a valuable resource for researchers involved in theoretical and experimental studies of strongly correlated materials, such as magnetic semiconductors, Fermi-Bose mixtures, and twisted bilayer graphene.

Introduction. Spontaneously Formed Nanoscale Inhomogenieties in Different Materials.- Magnetic Polarons and Related Transport Phenomena.- Some Model Systems. Internal Structure of Magnetic Polarons.- Charge Ordering and Phase Separation.- Phase Separation in Strongly Correlated Systems with Two Electron Bands.- Spin-state Transitions and Magnetic Instabilities.- Effects of Orbital Degrees of Freedom, Different Shapes of Polarons.- Systems with Imperfect Nesting and Phase Separation.

Prof. Dr. Maxim Yu. Kagan was born in Moscow in 1961, Corresponding Member of Russian Academy of Sciences, Principal scientist in the Theoretical Department of P. L Kapitza Institute for Physical Problems, Distinguished professor of Condensed Matter Physics in Moscow Institute of Electronics and Mathematics (MIEM) of the National Research University Higher School of Economics, Invited professor in San Sebastian, Spain.

From 2000 till 2018 an Executive Director of Russian Science Support Foundation, Winner of Presidential Award for young professors, Moscow, 1996 and Leverhulme Award (Leverhulme Professor), Loughborough University, UK, 2010, member of C5 IUPAP commission on Low Temperature Physics 2015-2022.

Prof. Kagan is renowned physicist with high international reputation. He made a significant contribution in the fields of condensed matter physics and investigations of novel materials, low temperature and statistical physics, author of 160 scientific publications and extended monography Modern trends in Superconductivity and Superfluidity published in Springer in 2013.

Dr. Kliment I. Kugel was born in Moscow in 1947, Leading Researcher in the Institute for Theoretical and Applied Electromagnetics of Russian Academy of Sciences, professor in Moscow Institute of Electronics and Mathematics (MIEM) of the National Research University Higher School of Economics. Fibonacci Prize in the field of magnetism and superconductivity (2019).  Visiting scientist in the Department of Physics, Loughborough University, UK (2002-2012)   and in the Institute of Physical and Chemical Research RIKEN, Wako, Japan (2012-2019).

Author of more than 180 scientific publications including several highly cited review articles. The main field of research during last ten years is the phase separation phenomena and superstructure formation in strongly correlated electron systems, such as manganites, cobaltites, cuprates, and graphene.

Prof. Dr. Alexander L. Rakhmanov was born in Novosibirsk in 1948, Laboratory Head in the Institute for Theoretical and Applied Electrodynamics of Russian Academy of Sciences, professor of Condensed Matter Physics in Moscow Institute of Physics and Technology (MIPT). Russian Government Prize in the field of science and technology (2012). Visiting scientist in the Institute of Physical and Chemical Research RIKEN, Wako, Japan (2004-2019).

Prof. Rakhmanov made a significant contribution in the fields of investigations of novel materials and superconductivity. He is the author of more than 200 scientific publications including reviews and monographs.

Dr. Artem O. Sboychakov was born in Moscow in 1978. He is Senior Researcher in the Institute for Theoretical and Applied Electrodynamics of Russian Academy of Sciences. Visiting scientist in the Institute of Physical and Chemical Research RIKEN, Wako, Japan (2006-2019).

Dr. Sboychakov is the author of about 100 scientific publications including review papers. His main research interest in recent years is the phase separation in the strongly correlated electron systems and the nature of many-body states in graphene-based materials.