A. G. Lebed

The physics of organic superconductors and conductors

Historical Surveys.- General Reviews.- Physical Properties of Quasi-One-Dimensional Organic Conductors.- Electron-Electron Interactions at Low Temperatures and Phase Transitions in Quasi-One-Dimensional Metals.- Magnetic Properties of Organic Conductors and Superconductors as Quantum Macroscopical Phenomena.- Physical Properties of Quasi-Two-Dimensional Superconductors and Conductors.- Layered Organic Conductors in Strong Magnetic Fields.- Ferroelectricity and Charge Disproportionation and Related Issues of the Interplay between Structural and Electronic Properties.- Interacting Electrons in Quasi-One-Dimensional Organic Conductors.- Measurements of Fermi-surface parameters of BEDT-salts under Extreme Conditions, Mechanisms for Superconductivity, Field-induced Phase Transitions and Exotic States of Matter.- Topical Reviews.- I. Unusual Properties of Metallic Phases.- Integer and Fractional Magic Angles Effects in Quasi-One-Dimensional Conductors.- Angular Magnetoresistance Oscillations in Quasi-One-Dimensional Conductors.- Microwave Spectroscopy of the Fermiology of Q1D and Q2D Organic Conductors.- II. Field-Induced Spin(Charge)-Density-Wave Phase and Three-Dimensional Quantum Hall Effect.- Field-Induced Spin-Density-Wave Phases in Quasi-One-Dimensional Conductor (TMTSF)2PF6.- Theory of Three-Dimensional Quantum Hall Effect.- Unconventional Density Waves in Organic Conductors.- Charge-Density-Wave Phases in a Magnetic Field.- Unusual High-Field States in Quasi-One-Dimensional Conductors Exhibiting Charge-Density-Waves.- Field-Induced Spin-Density-Wave Phases in (TMTSF)2ClO4.- III. Unconventional Superconducting Properties.- Unconventional Triplet and Exotic Type-IV Superconducting Phases in Organic Conductors.- Unconventional Superconductivity in Quasi-Two-Dimensional Organic Conductors.- Unconventional Properties in Quasi-Two-Dimensional Organic Superconductors.- Triplet Superconductivity in Quasi-One-Dimensional Conductors.- Theory of the Fulde-Ferrell-Larkin-Ovchinnikov State and Applications to Quasi-Low-Dimensional Organic Conductors.- IV. Electron Correlations in Organic Conductors.- Competition Between Spin-Density-Wave Order and Triplet Superconductivity in Bechgaard salts.- Charge ordering and local-singlet formation in quarter-filled band charge-transfer solids and oxides of early transition metals.- Correlations in Organic Charge Transfer Salts.- From Luttinger to Fermi liquids in organic conductors

IDENTIFICATION OF THE SUPERCONDUCTIVITY TYPE IN ORGANIC SUPERCONDUCTORS.

Two phenomena are pointed out which, if observed, would testify that the superconductivity in the Bechgaard salts belongs to the triplet pairing: excitation of the spin waves in the radio-frequency fields and the superconductivity restoration in high enough magnetic fields H||b*.

Theory of magnetic field-induced charge-density-wave phases

We elaborate an analytical theory of a cascade of magnetic field-induced charge-density-wave (FICDW) phases. It is shown that the following features distinguish it from the well-known spin-density-wave cascade: (1) the FICDW phases exist at temperatures much lower than the characteristic CDW transition temperature at H=0; (2) the cascade of the FICDW phases dramatically changes at certain directions of a magnetic field due to an interplay of Zeeman spin-splitting and electron motion along open Fermi surfaces. Theoretical results are compared with the recent experimental attempts to reveal FICDW phases in the organic conductors α-(ET)2MHg(SCN)4(M=K, Tl, Rb, etc.).

Angular Magnetoresistance Oscillations in Organic Conductors

We demonstrate that electron wave functions change their dimensionality at some commensurate directions of a magnetic field in conductors with open [quasi-one-dimensional (Q1D)] sheets of Fermi surface. These

Does the “quantized nesting model” properly describe the magnetic-field-induced spin-density-wave transitions?

1\mathrm{D}\ensuremath{\rightarrow}2\mathrm{D}

Instability of Metal Phase of the Q1D-Conductor in Magnetic Field

dimensional crossovers lead to delocalization of wave functions and are responsible for angular magnetoresistance oscillations. As an example, we show that suggested theory is in qualitative and quantitative agreement with the recent experimental data obtained on

Is gravitational mass of a composite quantum body equivalent to its energy

{(\mathrm{TMTSF})}_{2}{\mathrm{ClO}}_{4}

Non-Fermi-Liquid Crossovers in a Quasi-One-Dimensional Conductor in a Tilted Magnetic Field

conductor.

Does the Equivalence between Gravitational Mass and Energy Survive for a Composite Quantum Body

Theoretical reinvestigation of a so-called field-induced spin-density-wave (FISDW) phase diagram in a magnetic field in quasi-one-dimensional compounds (TMTSF)2X (X=PF6, ClO4, AsF6, etc.) has revealed some novel qualitative features. Among them are (1) the FISDW wave vector is never strictly quantized; and (2) the FISDW phase diagram consists of two regions: (a) “Quantum FISDW,” where there exist jumps of the FISDW wave vectors between different FISDW subphases and (b) “Quasiclassical FISDW,” where the jumps disappear above some critical points and only one FISDW phase (characterized by a wave vector oscillating with a magnetic field) exists. Both these features are due to taking account of the breaking of an electron-hole symmetry. They contradict the previous textbook theoretical results (including the calculations of the “Three Dimensional Quantum Hall Effect”) performed by means of the “Quantized Nesting Model” which explicitly assumes the existence of the electron-hole symmetry. We stress that some effects related to the phenomena described above were experimentally observed but not properly interpreted.

Cooper pairs with broken parity and spin-rotational symmetries in d-wave superconductors

Abstract A Q1D-metal with a layered structure is unstable against the SDW pairing in the presence of a weak magnetic field near the boundary where the SDW is suppressed by pressure The phase diagram of (TMTSF)2X-compounds is discussed.