Publications (51)
Theoretical Model for the Semimetal Yb_4As_3
Peter Fulde, Burkhard Schmidt, Peter Thalmeier
We present a model which can explain semiquantitatively a number of the unusual properties of \mbox{YbAs}. The structural phase transition at $T_{\text{c}}\simeq300\,\mbox{…
Full Self-Consistent Projection Operator Approach to Nonlocal Excitations in Solids
Yoshiro Kakehashi, Tetsuro Nakamura, Peter Fulde
A self-consistent projection operator method for single-particle excitations is developed. It describes the nonlocal correlations on the basis of a projection technique to the reta…
Obtaining Wannier Functions of a Crystalline Insulator within a Hartree-Fock approach: Applications to LiF and LiCl
Alok Shukla, Michael Dolg, Peter Fulde +1
An ab initio Hartree-Fock approach aimed at directly obtaining the localized orthogonal orbitals (Wannier functions) of a crystalline insulator is described in detail. The method i…
Excitations in Spin Chains and Specific-Heat Anomalies in Yb(4)As(3)
Burkhard Schmidt, Peter Thalmeier, Peter Fulde
An explanation is given for the observed magnetic-field dependence of the low-temperature specific heat coefficient of Yb(4)As(3). It is based on a recently developed model for tha…
Low Energy Excitations of Yb4As3 in a Magnetic Field
Yuri Kudasov, Gennadi Uimin, Peter Fulde +1
We discuss the effects of an applied magnetic field on the low energy excitations in the low temperature phase of Yb4As3. We show also why the magnetic interaction of the Yb{3+} io…
Spin Flip Torsion Balance
Peter Fulde, Stefan Kettemann
The spin flip of the conduction electrons at the interface of a ferromagnetic and a nonmagnetic part of a metallic wire, suspended between two electrodes, is shown to tort the wire…
Wavefunction-based correlated ab initio calculations on crystalline solids
Alok Shukla, Michael Dolg, Peter Fulde +1
We present a wavefunction-based approach to correlated ab initio calculations on crystalline insulators of infinite extent. It uses the representation of the occupied and the unocc…
Extended quantum U(1)-liquid phase in a three-dimensional quantum dimer model
Olga Sikora, Nic Shannon, Frank Pollmann +2
Recently, quantum dimer models, in which the system can tunnel between different classical dimer configurations, have attracted a great deal of interest as a paradigm for the study…
Critical magnetic field of ultrathin superconducting films and interfaces
Gertrud Zwicknagl, Simon Jahns, Peter Fulde
We derive an analytic expression for the temperature dependent critical magnetic field parallel to ultrathin superconducting films with Rashba spin-orbit interaction. Thereby we co…
Interaction of a Magnetic Impurity with Strongly Correlated Conduction Electrons
Tom Schork, Peter Fulde
We consider a magnetic impurity which interacts by hybridization with a system of strongly correlated conduction electrons. The latter are described by a Hubbard Hamiltonian. By me…
Kink Structure in the Quasiparticle Band of Doped Hubbard Systems
Yoshiro Kakehashi, Peter Fulde
By making use of the self-consistent projection operator method with high-momentum and high-energy resolutions, we find a kink structure in the quasiparticle excitation spectrum of…
Pre-K-Edge Structure on Anomalous X-Ray Scattering in LaMnO3
Manabu Takahashi, Jun-ichi Igarashi, Peter Fulde
We study the pre-K-edge structure of the resonant X-ray scattering for forbidden reflections (anomalous scattering) in LaMnO3, using the band calculation based on the local density…
A simplified method for the computation of correlation effects on the band structure of semiconductors
Uwe Birkenheuer, Peter Fulde, Hermann Stoll
We present a simplified computational scheme in order to calculate the effects of electron correlations on the energy bands of diamond and silicon. By adopting a quasiparticle pict…
Electron correlations for ground state properties of group IV semiconductors
Beate Paulus, Peter Fulde, Hermann Stoll
Valence energies for crystalline C, Si, Ge, and Sn with diamond structure have been determined using an ab-initio approach based on information from cluster calculations. Correlati…
Nanomechanical Detection of Itinerant Electron Spin Flip
Guiti Zolfagharkhani, Alexei Gaidarzhy, Pascal Degiovanni +3
Spin is an intrinsically quantum property, characterized by angular momentum. A change in the spin state is equivalent to a change in the angular momentum or mechanical torque. Thi…
Correlation effects in ionic crystals: I. The cohesive energy of MgO
Klaus Doll, Michael Dolg, Peter Fulde +1
High-level quantum-chemical calculations, using the coupled-cluster approach and extended one-particle basis sets, have been performed for (Mg2+)n (O2-)m clusters embedded in a Mad…
Wavefunctions for large electronic systems
Peter Fulde
Wavefunctions for large electron numbers suffer from an exponential growth of the Hilbert space which is required for their description. In fact, as pointed out by W. Kohn, for ele…
Influence of electron correlations on ground-state properties of III-V semiconductors
Simon Kalvoda, Beate Paulus, Peter Fulde +1
Lattice constants and bulk moduli of eleven cubic III-V semiconductors are calculated using an ab initio scheme. Correlation contributions of the valence electrons, in particular,…
Covalency and vibronic couplings make a nonmagnetic j=3/2 ion magnetic
Lei Xu, Nikolay A. Bogdanov, Andrew Princep +3
For 4 and 5 spin-orbit-coupled electron configurations, the notion of nonmagnetic j=3/2 quartet ground state discussed in classical textbooks is at odds with the observed…
A Hartree-Fock ab initio band-structure calculation employing Wannier-type orbitals
Martin Albrecht, Alok Shukla, Michael Dolg +2
An ab initio Wannier-function-based approach to electronic ground-state calculations for crystalline solids is outlined. In the framework of the linear combination of atomic orbita…
Orbital Localization and Delocalization Effects in the U 5f^2 Configuration: Impurity Problem
Mikito Koga, Wenjian Liu, Michael Dolg +1
Anderson models, based on quantum chemical studies of the molecule of U(C_8H_8)_2, are applied to investigate the problem of an U impurity in a metal. The special point here is tha…
Electron correlation effects in diamond: a wave-function quantum chemistry study of the quasiparticle band structure
Alexandrina Stoyanova, Alexander O. Mitrushchenkov, Liviu Hozoi +2
The quasiparticle bands of diamond, a prototype covalent insulator, are herein studied by means of wave-function electronic-structure theory, with emphasis on the nature of the cor…
Wavefunctions for large systems as basis for electronic structure calculations
Peter Fulde
Electronic structure calculations for solids based on many-electron wavefunctions have been hampered by the argument that for large electron numbers wavefunctions are not a legitim…
A Quantum Chemical Approach to Cohesive Properties of NiO
Klaus Doll, Michael Dolg, Peter Fulde +1
We apply ab-initio quantum chemical methods to calculate correlation effects on cohesive properties of NiO, thereby extending a recently proposed scheme to transition metal oxides…
Correlated Persistent Tunneling Currents in Glasses
Stefan Kettemann, Peter Fulde, Peter Strehlow
Low temperature properties of glasses are derived within a generalized tunneling model, considering the motion of charged particles on a closed path in a double-well potential. The…
Nonlocal Excitation Spectra in 2D Doped Hubbard Model
Yoshiro Kakehashi, Peter Fulde
Single-particle excitation spectra of the two-dimensional Hubbard model on the square lattice near half filling and at zero temperature are investigated on the basis of the self-co…
Parity Effects in Stacked Nanoscopic Quantum Rings
Kang-Hun Ahn, Peter Fulde
The ground state and the dielectric response of stacked quantum rings are investigated in the presence of an applied magnetic field along the ring axis. For odd number of rings…
Strongly correlated electrons on frustrated lattices
Peter Fulde, Frank Pollmann, Erich Runge
We give an overview of recent work on charge degrees of freedom of strongly correlated electrons on geometrically frustrated lattices. Special attention is paid to the checkerboard…
Quantum Ice : a quantum Monte Carlo study
Nic Shannon, Olga Sikora, Frank Pollmann +2
Ice states, in which frustrated interactions lead to a macroscopic ground-state degeneracy, occur in water ice, in problems of frustrated charge order on the pyrochlore lattice, an…
Strongly correlated electrons
Peter Fulde, Peter Thalmeier, Gertrud Zwicknagl
We review theoretical concepts and models for materials with strongly correlated d- or f electrons. We discuss low-energy effective models and the renormalized band method for Ce-b…
Ab-Initio Calculation of the Metal-Insulator Transition in Lithium rings
Beate Paulus, Krzysztof Rosciszewski, Peter Fulde +1
We study how the Mott metal-insulator transition (MIT) is affected when we have to deal with electrons with different angular momentum quantum numbers. For that purpose we apply ab…
Dielectric response of cylindrical nanostructures in a magnetic field
Peter Fulde, Alexander Ovchinnikov
We study the magnetic field dependence of the dielectric response of large cylindrical molecules such as nanotubes. When a field-induced level crossing takes place, an applied elec…
Ground-state properties of rutile: electron-correlation effects
Krzysztof Rosciszewski, Klaus Doll, Beate Paulus +2
Electron-correlation effects on cohesive energy, lattice constant and bulk compressibility of rutile are calculated using an ab-initio scheme. A competition between the two groups…
Metal-insulator transition of the Kagome lattice fermions at 1/3 filling
Satoshi Nishimoto, Masaaki Nakamura, Aroon O'Brien +1
We discuss the metal-insulator transition of the spinless fermion model on the Kagomé lattice at 1/3-filling. The system is analyzed using exact diagonalization, the density-matri…
Bound state of 4-excitation and magnetic resonance in unconventional superconductors
Alireza Akbari, Ilya Eremin, Peter Thalmeier +1
We analyze the influence of unconventional superconductivity on crystalline electric field (CEF) excitations of rare earth ions in novel superconductors. We show that resonant magn…
Topological states in pyrochlore iridates: long-range anisotropy strongly competing with spin-orbit interaction
Liviu Hozoi, H. Gretarsson, J. P. Clancy +7
In the search for topological phases in correlated electron systems, iridium-based pyrochlores A2Ir2O7 -- materials with 5d transition-metal ions -- provide fertile grounds. Severa…
Strongly correlated fermions on a kagome lattice
Aroon O'Brien, Frank Pollmann, Peter Fulde
We study a model of strongly correlated spinless fermions on a kagome lattice at 1/3 filling, with interactions described by an extended Hubbard Hamiltonian. An effective Hamiltoni…
Role of the action function in defining electronic wavefunctions for large systems
Peter Fulde
The dimension of the Hilbert space needed for the description of an interacting electron system increases exponentially with electron number . As pointed out by W. Kohn this exp…
Cohesive energies of cubic III-V semiconductors
Beate Paulus, Peter Fulde, Hermann Stoll
Cohesive energies for twelve cubic III-V semiconductors with zincblende structure have been determined using an ab-initio scheme. Correlation contributions, in particular, have bee…
Theory of Spin Exciton in the Kondo Semiconductor
Alireza Akbari, Peter Thalmeier, Peter Fulde
The Kondo semiconductor exhibits a spin and charge gap of approximately 15 meV. Close to the gap energy narrow dispersive collective excitations were identified by prev…
Ab initio Green's function formalism for band structures
Christian Buth, Uwe Birkenheuer, Martin Albrecht +1
Using the Green's function formalism, an ab initio theory for band structures of crystals is derived starting from the Hartree-Fock approximation. It is based on the algebraic diag…
Fractional charges in pyrochlore lattices
Peter Fulde, Karlo Penc, Nic Shannon
A pyrochlore lattice is considered where the average electron number of electrons per site is half--integer, concentrating on the case of exactly half an electron per site. Strong…
Fermionic quantum dimer and fully-packed loop models on the square lattice
Frank Pollmann, Joseph J. Betouras, Kirill Shtengel +1
We consider fermionic fully-packed loop and quantum dimer models which serve as effective low-energy models for strongly correlated fermions on a checkerboard lattice at half and q…
Eliashberg theory of superconductivity and inelastic rare-earth impurity scattering in filled skutterudite LaPrOsSb
Jun Chang, Ilya Eremin, Peter Thalmeier +1
We study the influence of inelastic rare-earth impurity scattering on electron-phonon mediated superconductivity and mass renormalization in (LaPr)OsSb c…
On Metal-Insulator Transitions due to Self-Doping
Stefan Blawid, Hoangh Anh Tuan, Takashi Yanagisawa +1
We investigate the influence of an unoccupied band on the transport properties of a strongly correlated electron system. For that purpose, additional orbitals are coupled to a Hubb…
Towards a quantum-chemical description of crystalline insulators: A Wannier-function-based Hartree-Fock study of Li2O and Na2O
Alok Shukla, Michael Dolg, Peter Fulde +1
A recently proposed approach for performing electronic-structure calculations on crystalline insulators in terms of localized orthogonal orbitals is applied to the oxides of lithiu…
Ground state of many-electron systems based on the action function
Peter Fulde
The Hilbert space for an interacting electron system increases exponentially with electron number . This limits the concept of wavefunctions based on solutions of the SchrÃ…
Ab initio calculation of d-d excitations in quasi-one-dimensional Cu d9 correlated materials
Hsiao-Yu Huang, Nikolay A. Bogdanov, Liudmila Siurakshina +3
With wavefunction-based electronic-structure calculations we determine the Cu d-d excitation energies in quasi-one-dimensional spin-chain and ladder copper oxides. A complete set o…
Ab Initio determination of Cu 3d orbital energies in layered copper oxides
Liviu Hozoi, Liudmila Siurakshina, Peter Fulde +1
It has long been argued that the minimal model to describe the low-energy physics of the high-Tc superconducting cuprates must include copper states of other symmetries besides the…
Dealing with the exponential wall in electronic structure calculations
Peter Fulde, Hermann Stoll
An alternative to Density Functional Theory are wavefunction based electronic structure calculations for solids. In order to perform them the Exponential Wall (EW) problem has to b…
Ground-state wavefunction of macroscopic electron systems
Peter Fulde
Wavefunctions for large electron numbers are plagued by the Exponential Wall Problem (EWP), i.e., an exponential increase in the dimensions of Hilbert space with . Therefore…