Showing papers on "Mott transition published in 1990"
842 citations
Abstract: The following properties have been measured for mercury clusters: (1) ionisation potentials of Hgn by electron-impact ionisation, (2) dissociation energies of Hg+n, and (3) mass spectra for negatively charged mercury cluster ions (n 3). Cohesive energies for neutral and ionised Hg clusters have been calculated from the data. The transitions in chemical binding are discussed. For small clusters Hgn is van der Waals bound (n⩽ 13), the binding changes to covalent for 30 ⩽n⩽ 70, and then to metallic (n 100). A sudden transition from covalent to metallic bonding is observed. It is discussed whether this can be considered as being analogous to a Mott transition for a finite system. The experimentally observed transitions in chemical bonding are much more pronounced than those calculated in a tight-binding calculation. This points to strong correlation effects in Hg clusters.
90 citations
TL;DR: In this paper, the competition between the Mott transition and Fermi surface nesting in a Cu-O2 plane is studied in the limit of infinite on-site Coulomb repulsion.
Abstract: Competition between the Mott transition and Fermi surface nesting in a Cu-O2 plane is studied in the limit of infinite on-site Coulomb repulsion. By incorporating direct O-O hopping, the nesting condition (Fermi surface at van Hove singularity) can be shifted away from half filling. The Mott transition (actually a transition to a charge transfer insulator) remains at half filling, driven by electron correlation effects, herein described via a slave boson formalism. Away from half-filling, electron-phonon coupling leads to a phase separation into the insulating phase near half filling, and a metallic phase close to the van Hove singularity. The consequences of this phase separation for high-Tc superconductivity are briefly discussed.
76 citations
TL;DR: In this paper, a solvable model of d = 1 spinless fermions at half-filling which exhibits a Mott transition is studied in detail, and many response functions are computed: at zero and nonzero temperatures, in the insulating and metallic sites, at the transition, and at q ≃ 0, 2kF.
Abstract: A solvable model of d = 1 spinless fermions at half-filling which exhibits a Mott transition is studied in detail. Many response functions are computed: at zero and nonzero temperatures, in the insulating and metallic sites, at the transition, and at q ≃ 0, 2kF. Some quantities are computed exactly, others only upto a scale factor. Some results are old, but mentioned here for completeness. Some are rederived using new tools such as conformal invariance. The rest are new. Next, the effect of randomness on the Mott state is explored. It is found, on the basis of Imry-Ma type arguments that no matter how large the gap is, the Mott insulator turns into an Anderson insulator immediately.
71 citations
TL;DR: The transport properties of a strongly (antiferromagnetically) correlated electron system in the temperature regime where the Fermi-liquid coherence ceases to exist is considered, and the resistivity is linear in temperature, the thermal conductivity is almost temperature independent obeying approximately the Wiedemann-Franz law, while the Hall coefficient acquires a temperature dependence.
Abstract: We consider the transport properties of a strongly (antiferromagnetically) correlated electron system in the temperature regime where the Fermi-liquid coherence ceases to exist. We find that the resistivity is linear in temperature, the thermal conductivity is almost temperature independent obeying approximately the Wiedemann-Franz law, while the Hall coefficient acquires a temperature dependence. The sign of the thermopower and Hall coefficient are hole-like. We calculate the residual resistivity caused by a random potential using the slave-boson technique. The disorder changes the slope of the temperature-dependent resistivity, but the Fermi surface remains relatively sharp.
39 citations
Journal Article•
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TL;DR: A review with 23 refs on the Mott transition is given in this article, where the metal-insulator transition as a function of the lattice const. a is considered.
Abstract: A review with 23 refs. on the Mott transition (metal-insulator transition as a function of the lattice const. a).
32 citations
TL;DR: It is determined that the materials are in a regime controlled by proximity to a Mott transition and that magnetic correlations play an essential role in high-temperature superconductors.
Abstract: The lattice Anderson model believed to be relevant to high-temperature superconductors and heavy-fermion metals exhibits a variety of different behaviors, including mixed-valence, heavy-fermion, and Mott-insulating states. We determine, via an auxiliary-boson mean-field theory, the parameter regimes in which these behaviors exist. For the two-dimensional CuO{sub 2} Anderson model we calculate the susceptibility, and quasiparticle plasma frequency. By comparing these to specific-heat, susceptibility and optical data for high-{Tc} superconductors, we determine that the materials are in a regime controlled by proximity to a Mott transition and that magnetic correlations play an essential role.
29 citations
TL;DR: In this article, the electronic properties of almost localized quasiparticles and the theoretical interpretation of the observed discontinuous metal-insulator (Mott) transitions in V 2 O 3 system, induced by electron-electron interaction are discussed.
26 citations
01 Jan 1990
TL;DR: In this article, the metal-insulator (MI) transition in Si:P is reviewed, and it has become a prototype MI transition bearing features both of an Anderson transition due to the statistical distribution of donor atoms and of a Mott transition because of electron-electron interactions.
Abstract: Recent experiments on the metal-insulator (MI) transition in Si:P are reviewed. This transition occurs as a function of phosphorus concentration N at N c ≈3.5·1018 cm−3. It has become a prototype MI transition bearing features both of an Anderson transition due to the statistical distribution of donor atoms and of a Mott transition due to electron-electron interactions. In the metallic regime above N c the temperature dependence of the electrical conductivity e at low temperatures is governed by localization and electron-interaction effects. Upon approaching N c , e goes to zero as(N−N c ) v with v ≈ 0.5 for uncompensated and v ≈ 1 for compensated Si:P. This difference may lie in the importance of electron-electron interactions in the former. In the vicinity of the MI transition both delocalized and localized electrons are simultaneously present as evidenced by a large number of different experiments such as magnetic susceptibility, specific heat and magnetic resonance. In particular, the magnetic field dependence of the specific heat allows a detailed analysis of the contributions of localized and itinerant electrons. A field-induced shift towards localization is clearly observed. Finally, the delocalized electrons exhibit a well-defined plasma edge in the far-infrared reflectivity.
18 citations
TL;DR: If a system of hard-core particles in {ital d}=2 is given to be a Mott insulator, then the charge must form a commensurate charge-density wave, which implies a breakdown of lattice-translation symmetry.
Abstract: We explore the connection between Mott-insulating behavior and the breakdown of lattice-translation symmetry. We find that if a system of hard-core particles in {ital d}=2 is given to be a Mott insulator, then the charge must form a commensurate charge-density wave. This is true for particles of any statistics. Our result is based on duality arguments and does not seem to depend on the details of the Hamiltonian. For average site-occupation number {ital n}{lt}1, this implies a breakdown of lattice-translation symmetry.
15 citations
TL;DR: In this paper, the antiferromagnetic insulating phase in La 2- x Sr x CuO 4 was studied by beginning from a doped Fermi-liquid phase, which undergoes a spin-density-wave-like transition as doping is reduced.
Abstract: The antiferromagnetic insulating phase in La 2- x Sr x CuO 4 is studied by beginning from a doped Fermi-liquid phase, which undergoes a spin-density-wave-like transition as doping is reduced. Strong correlation effects renormalize the bands near half-filling, until the susceptibility satisfies a Stoner criterion. The ordered phase is predicted to become more incommensurate as doping is increased. A mode-mode coupling formalism is introduced to study the effect of interlayer coupling.
TL;DR: In this article, the isostructural γ-α phase transition of Ce is studied by means of FLAPW band calculations carried out for four different electronic structures of Ce.
Abstract: The isostructural γ–α phase transition of Ce is studied by means of FLAPW band calculations carried out for four different electronic structures of Ce. The calculated results support the picture of a 4f localized-itinerant transition at the γ–α transition.
[Russian Text Ignored].
TL;DR: The existence of the two corresponding ionization phases with different optical properties is shown to result in optical bistability (OB), which is quite similar to the increasing-absorption (resonatorless) OB but has some peculiarities of its own.
Abstract: Within the framework of a simple numerical model, we investigate the optical properties of a laser-excited direct-band-gap semiconductor (CdS) in the case when both free and bound electron-hole pairs are present. At low temperatures the ionization of excitons proceeds via a first-order phase transition, which is closely related to the Mott transition, and we argue that in direct-band-gap semiconductors it is not suppressed by the electron-hole liquid condensation, as it is in indirect-band-gap materials. The existence of the two corresponding ionization phases with different optical properties is shown to result in optical bistability (OB), which is quite similar to the increasing-absorption (resonatorless) OB but has some peculiarities of its own. Our model also predicts another optical manifestation of this ionization phase transition\char22{}the possibility of absorption oscillations at resonant excitation of excitons.
Journal Article•
TL;DR: The Gutzwiller method has been applied to the one-dimensional Emery model and a metal-insulator transition has been found when the number of electrons at the copper site is one and the whole electron number is three as mentioned in this paper.
Abstract: The Gutzwiller method has been applied to the one-dimensional Emery model and a metal-insulator transition has been found when the number of electrons at the copper site is one and the whole electron number is three. The parameter-dependence of the critical correlation, at which the transition occurs, has been calculated. The charge-transfer character of the arising gap has been determined.
Journal Article•
TL;DR: In this paper, the Mott-Hubbard gap is described in a rotationally and translationally invariant approach similar to the alloy analogy used earlier, and it is pointed out that in the strongly correlated metal, quantum fluctuation effects not considered so far could destroy long range magnetic order and lead to a non-Fermi liquid metallic state strongly coupled to a spin liquid.
Abstract: The opening up to the Mott-Hubbard gap is described in a rotationally and translationally invariant approach similar to the alloy analogy used earlier. It is pointed out that in the strongly correlated metal, quantum fluctuation effects not considered so far could destroy long range magnetic order and lead to a non-Fermi liquid metallic state strongly coupled to a spin liquid.
TL;DR: In this article, the effect of Hund's second rule is included not only in the total energy, but also in the eigenvalue splittings which are required in the energy band calculation for the solid.
Abstract: A novel technique for treating orbital polarization is presented. The single electron eigenvalue shifts that emanated from the orbital polarization are of the form − E 3 Lm l , where E 3 is the Racah parameter, L is the orbital moment and m l the azimuthal quantum number. Thereby the effect of Hund's second rule is included not only in the total energy, but also in the eigenvalue splittings which are required in the energy band calculation for the solid. The calculations also incorporate the exchange and correlation potential in the local spin density approximation as well as the spin-orbit coupling. The self-consistently calculated equation-of-state for the light lanthanide Ce is presented. The observed volume collapse is well described by the parameter free calculations and accordingly the volume collapse in Ce is described as a Mott transition of the 4f electron.
TL;DR: The metal-insulator transition for atomic hydrogen on an ordered lattice at zero degrees kelvin was estimated by the diffusion Monte Carlo algorithm with simple variational trial wave functions to occur at an interatomic separation of 4.4 Bohr radii.
Abstract: The metal-insulator transition (Mott transition) for atomic hydrogen on an ordered lattice at zero degrees kelvin is estimated by the diffusion Monte Carlo algorithm with simple variational trial wave functions to occur at an interatomic separation of 4.4 Bohr radii.
TL;DR: In this paper, a scaling theory of the metal insulator transition due to correlations is extended to take into account the multicritical character of this instability at zero temperature as required for the vanishing of the compressibility.
Abstract: A recently proposed scaling theory of the metal insulator transition due to correlations is extended to take into account the multicritical character of this instability at zero temperature as required for the vanishing of the compressibility.