Annalen der Physik

Cover image for Vol. 523 Issue 8‐9

Special Issue: Special Topic Issue “Electronic Correlations in Models and Materials”

August 2011

Volume 523, Issue 8-9

Pages 583–758

Issue edited by: Peter van Dongen, Marcus Kollar, Thomas Pruschke

  1. Cover Picture

    1. Top of page
    2. Cover Picture
    3. Issue Information
    4. Contents
    5. Preface
    6. Original Papers
    1. Cover Picture: Ann. Phys. 8–9/2011

      Version of Record online: 13 SEP 2011 | DOI: 10.1002/andp.201190008

  2. Issue Information

    1. Top of page
    2. Cover Picture
    3. Issue Information
    4. Contents
    5. Preface
    6. Original Papers
    1. Issue Information: Ann. Phys. 8–9/2011

      Version of Record online: 13 SEP 2011 | DOI: 10.1002/andp.201152398

  3. Contents

    1. Top of page
    2. Cover Picture
    3. Issue Information
    4. Contents
    5. Preface
    6. Original Papers
  4. Preface

    1. Top of page
    2. Cover Picture
    3. Issue Information
    4. Contents
    5. Preface
    6. Original Papers
    1. Preface (pages 589–590)

      Peter van Dongen, Marcus Kollar and Thomas Pruschke

      Version of Record online: 13 SEP 2011 | DOI: 10.1002/andp.201010471

  5. Original Papers

    1. Top of page
    2. Cover Picture
    3. Issue Information
    4. Contents
    5. Preface
    6. Original Papers
    1. Quantum critical behavior of heavy fermions: Quasiparticles in the Gaussian fluctuation regime (pages 591–598)

      P. Wölfle and E. Abrahams

      Version of Record online: 13 SEP 2011 | DOI: 10.1002/andp.201100015

      Landau quasiparticle (qp) theory may be extended into the non-Fermi liquid regime of metallic compounds near a quantum critical point (QCP), provided the width of the quasiparticle states is less than their energy. Sufficiently far from the QCP, when the critical fluctuations are non-interacting, their influence on the qp properties may be calculated in a controlled way.

    2. Electron-electron interactions and the metal-insulator transition in heavily doped silicon (pages 599–611)

      H. v. Löhneysen

      Version of Record online: 13 SEP 2011 | DOI: 10.1002/andp.201100034

      Thumbnail image of graphical abstract

      The metal-insulator (MI) transition in Si:P can be tuned by varying the P concentration or – for barely insulating samples – by application of uniaxial stress S. On-site Coulomb interactions lead to the formation of localized magnetic moments and the Kondo effect on the metallic side, and to a Hubbard splitting of the donor band on the insulating side.

    3. Strong electron correlations in FeSb2 (pages 612–620)

      P. Sun, M. Søndergaard, B.B. Iversen and F. Steglich

      Version of Record online: 13 SEP 2011 | DOI: 10.1002/andp.201100033

      FeSb2 has been recently identified as a new model system for studying many-body renormalizations in a d-electron based narrow gap semiconducting system, strongly resembling FeSi. The electron-electron correlations in FeSb2 manifest themselves in a wide variety of physical properties including electrical and thermal transport, optical conductivity, magnetic susceptibility, specific heat and so on. The authors review some of the properties that form a set of experimental evidences revealing a significant role of correlation effects in FeSb2.

    4. Anomalous criticality near semimetal-to-superfluid quantum phase transition in a two-dimensional Dirac cone model (pages 621–628)

      B. Obert, S. Takei and W. Metzner

      Version of Record online: 13 SEP 2011 | DOI: 10.1002/andp.201100039

      The authors analyze the scaling behavior at and near a quantum critical point separating a semimetallic from a superfluid phase. To this end they compute the renormalization group flow for a model of attractively interacting electrons with a linear dispersion around a single Dirac point. They study both ground state and finite temperature properties.

    5. Theory of pseudogap and superconductivity in doped Mott insulators (pages 629–637)

      M. Imada, Y. Yamaji, S. Sakai and Y. Motome

      Version of Record online: 13 SEP 2011 | DOI: 10.1002/andp.201100028

      Thumbnail image of graphical abstract

      Underdoped Mott insulators provide us with a challenge of many-body physics. Recent renewed understanding is discussed in terms of the evolution of pole and zero structure of the single-particle Green's function. Pseudogap as well as Fermi arc/pocket structure in the underdoped cuprates is well reproduced from the recent cluster extension of the dynamical mean-field theory. Emergent coexisting zeros and poles set the underdoped Mott insulator apart from the Fermi liquid, separated by topological transitions. The cofermion proposed as a generalization of exciton in the slave-boson framework accounts for the origin of the zero surface formation. The cofermion-quasiparticle hybridization gap offers a natural understanding of the pseudogap and various unusual Mottness. Furthermore the cofermion offers a novel pairing mechanism, where the cofermion has two roles: It reinforces the Cooper pair as a pair partner of the quasiparticle and acts as a glue as well. It provides a strong insight for solving the puzzle found in the dichotomy of the gap structure.

    6. Order-parameter anisotropies in the pnictides: An optimization principle for multi-band superconductivity (pages 638–644)

      W. Hanke, Ch. Platt and R. Thomale

      Version of Record online: 13 SEP 2011 | DOI: 10.1002/andp.201100035

      Thumbnail image of graphical abstract

      Using general arguments of an optimization taking place between the pair wave function and the repulsive part of the electron-electron interaction, the authors analyze the superconducting gap in materials with multiple Fermi-surface (FS) pockets, with exemplary application to two proto-type ferropnictide setups. The main point is to show that the SC state, its gap, and, in particular, its anisotropy in momentum space is determined by an optimization which determines and optimizes the interplay between the attractive interaction in the SC-channel and the Coulomb repulsion.

    7. Lattice vibrations in KCuF3 (pages 645–651)

      J. Deisenhofer, M. Schmidt, Zhe Wang, Ch. Kant, F. Mayr, F. Schrettle, H.-A. Krug von Nidda, P. Ghigna, V. Tsurkan and A. Loidl

      Version of Record online: 13 SEP 2011 | DOI: 10.1002/andp.201100026

      Thumbnail image of graphical abstract

      The authors report on polarization dependent reflectivity measurements in KCuF3 in the far-infrared frequency regime. The observed IR active phonons at room temperature are in agreement with the expected modes for tetragonal symmetry. A splitting of one mode already at 150 K and the appearance of a new mode in the vicinity of the Néel temperature is observed.

    8. Electron-lattice correlations and phase transitions in CMR manganites (pages 652–663)

      V. Moshnyaga and K. Samwer

      Version of Record online: 13 SEP 2011 | DOI: 10.1002/andp.201100040

      Thumbnail image of graphical abstract

      Interrelations between global and local structure and magnetism and transport in three-dimensional perovskite manganites is reviewed and compared with recent studies on thin films and superlattices. The concept of correlated Jahn-Teller (JT) polarons is discussed within the phase separation scenario; their role in the local and global structural modifications of manganites is demonstrated. fig.

    9. Nonlinear transport through quantum dots studied by the time-dependent DMRG (pages 664–671)

      S. Kirino and K. Ueda

      Version of Record online: 13 SEP 2011 | DOI: 10.1002/andp.201100031

      Recent developments on studies of transport through quantum dots obtained by applying the time-dependent density matrix renormalization group method are summarized. Some new aspects of Kondo physics which appear in nonequilibrium steady states are discussed both for the single dot case and for the serially coupled double-quantum-dot case.

    10. Thinking locally: Reflections on Dynamical Mean-Field Theory from a high-temperature/high-energy perspective (pages 672–681)

      A. Georges

      Version of Record online: 13 SEP 2011 | DOI: 10.1002/andp.201100042

      When spatial correlations are short-range, the physics of strongly correlated systems is controlled by local quantum fluctuations. In those regimes, Dynamical Mean-Field Theory can be viewed as a `compass' which provides guidance on the relevant degrees of freedom and their effective dynamics over intermediate energy scales. These intermediate energy scales and associated crossovers play a crucial role in the physics of strongly correlated materials.

    11. Various scenarios of metal-insulator transition in strongly correlated materials (pages 682–688)

      J. Kuneš and V.I. Anisimov

      Version of Record online: 13 SEP 2011 | DOI: 10.1002/andp.201100027

      Thumbnail image of graphical abstract

      The authors review their investigations of electronic properties of strongly correlated materials using the combination of first principles electronic band structures and the dynamical mean-field theory, so called LDA+DMFT method. Their investigations focus on two phenomena, the spin state transitions and their relationship to the metal-insulator transition, and the effect of hybridization between correlated and ligand orbitals in charge-transfer type materials.

    12. Anisotropic two-orbital Hubbard model: Single-site versus cluster Dynamical Mean-Field Theory (pages 689–697)

      H. Lee, Y.-Z. Zhang, H.O. Jeschke and R. Valentí

      Version of Record online: 13 SEP 2011 | DOI: 10.1002/andp.201100021

      The anisotropic two-orbital Hubbard model with different bandwidths and degrees of frustration in each orbital is investigated in the framework of both single-site dynamical mean-field theory (DMFT) as well as its cluster extension (DCA) for clusters up to four sites combined with a continuous-time quantum Monte Carlo algorithm. This model shows a rich phase diagram which includes the appearance of orbital selective phase transitions, non-Fermi liquid behavior as well as antiferromagnetic metallic states.

    13. Ab initio calculations with the dynamical vertex approximation (pages 698–705)

      A. Toschi, G. Rohringer, A.A. Katanin and K. Held

      Version of Record online: 13 SEP 2011 | DOI: 10.1002/andp.201100036

      Thumbnail image of graphical abstract

      The authors propose an approach for the ab initio calculation of materials with strong electronic correlations which is based on all local (fully irreducible) vertex corrections beyond the bare Coulomb interaction. It includes the so-called GW and dynamical mean field theory and important non-local correlations beyond, with a computational effort estimated to be still manageable.

    14. Superperturbation theory on the real axis (pages 706–714)

      C. Jung, A. Wilhelm, H. Hafermann, S. Brener and A. Lichtenstein

      Version of Record online: 13 SEP 2011 | DOI: 10.1002/andp.201100043

      Thumbnail image of graphical abstract

      In this article the authors formulate the superperturbation theory for the Anderson impurity model on the real axis. The resulting impurity solver allows to evaluate dynamical quantities without numerical analytical continuation by the maximum entropy method or Padé approximants.

    15. Renormalized perturbation theories of Anderson localization: Self-consistent two-particle vertices (pages 715–723)

      V. Janiš and V. Pokorný

      Version of Record online: 13 SEP 2011 | DOI: 10.1002/andp.201100025

      The effects of quantum coherence on two-particle vertex functions due to impurity scattering of electrons are studied. The authors use the diagrammatic perturbation expansion in the impurity potential and analyze possible ways how to introduce renormalizations on the two-particle level.

    16. Adiabatic continuity and broken symmetry in many-electron systems: A variational perspective (pages 724–731)

      D. Baeriswyl

      Version of Record online: 13 SEP 2011 | DOI: 10.1002/andp.201100044

      Variational wave functions are very useful for describing the panoply of ground states found in interacting many-electron systems. Some particular trial states are “adiabatically” linked to a reference state, from which they borrow the essential properties. A prominent example is the Gutzwiller ansatz, where one starts with the filled Fermi sea. To describe symmetry breaking, the reference state has to be modified accordingly.

    17. Extending the Gutzwiller approximation for liquid 3He by including intersite correlations (pages 732–740)

      D. Müller, S. Pilgram, T.M. Rice and M. Sigrist

      Version of Record online: 13 SEP 2011 | DOI: 10.1002/andp.201100023

      Thumbnail image of graphical abstract

      The simple Gutzwiller approximation, applied to the approach to Mott localization in a half-filled band Hubbard model, gives a remarkably good description of the properties of liquid 3He as the liquid-solid transition is approached under pressure. Here the Gutzwiller approximation is extended to incorporate correlations between nearest neighbors.

    18. Exact ground states for polyphenylene type of hexagon chains (pages 741–750)

      R. Trencsényi, K. Gulácsi, E. Kovács and Z. Gulácsi

      Version of Record online: 13 SEP 2011 | DOI: 10.1002/andp.201100022

      Thumbnail image of graphical abstract

      A technique based on positive semidefinite operator properties has been used in deducing exact ground states for hexagon chains of polyphenylene type (hexagons interconnected by bonds build up the 1D periodic structure), placed in a constant external magnetic field perpendicular to the surface containing the system.

    19. The last word in strong correlations (pages 751–758)

      R. Shankar

      Version of Record online: 13 SEP 2011 | DOI: 10.1002/andp.201100017

      In the Fractional Quantum Hall Effect (FQHE), in the noninteracting limit, only a fraction ν of the Lowest Landau Level (LLL) is occupied, producing a huge degeneracy. Interactions lift this degeneracy and mix in higher LL's. In the limit in which we ignore all but the LLL, the kinetic energy is an irrelevant constant and the ratio of potential to kinetic energy is essentially infinite, making this the most strongly correlated problem imaginable. The Hamiltonian theory of the FQHE deals with this problem with some success.