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Full-Text Articles in Physics
Dispersion Anomalies Induced By The Low-Energy Plasmon In The Cuprates, R. S. Markiewicz, A. Bansil
Dispersion Anomalies Induced By The Low-Energy Plasmon In The Cuprates, R. S. Markiewicz, A. Bansil
Arun Bansil
We discuss the characteristic effects of the electron plasmon interaction resulting from the ~ 1 eV plasmon, which is a universal feature in the cuprates. Using the framework of a one-band tight binding model, we identify signatures of this low energy plasmon in the electronic structure of metallic overdoped Bi₂212 as well as half-filled insulating SCOC. The electron-plasmon interaction is found to yield renormalizations near the Fermi energy in reasonable accord with experimental observations, and to produce dispersion anomalies at higher energies.
Dielectric Signatures Of Lattice Instabilities At 32k And 245k In $La_{2-Y}Sr_{Y}Mo_{4+X}$ (M=Cu,Ni) Cuprates And Nickelates, P. Parimi, N. Hakim, F. Chou, S. Cheong, S. Sridhar
Dielectric Signatures Of Lattice Instabilities At 32k And 245k In $La_{2-Y}Sr_{Y}Mo_{4+X}$ (M=Cu,Ni) Cuprates And Nickelates, P. Parimi, N. Hakim, F. Chou, S. Cheong, S. Sridhar
Srinivas Sridhar
New dielectric transitions are observed at common temperatures 32K and 245K, in isostructural $La_{2}CuO_{4+x}$ and $La_{5/3}Sr_{1/3}NiO_{4},$ that are signatures of local lattice (octahedral) instabilities. The present dielectric transitions reveal new aspects of the phase diagram of the perovskite cuprates and nickelates. They suggest that competition and coexistence of superconductivity with dielectricity occurs that is analogous to that between superconductivity and anti-ferromagnetism. These results also indicate that inhomogeneous electronic states, such as charge stripes and oxygen ordering, are strongly connected to underlying lattice instabilities.
Dispersion Of Ordered Stripe Phases In The Cuprates, R. S. Markiewicz
Dispersion Of Ordered Stripe Phases In The Cuprates, R. S. Markiewicz
Robert Markiewicz
A phase separation model is presented for the stripe phase of the cuprates, which allows the doping dependence of the photoemission spectra to be calculated. The idealized limit of a well-ordered array of magnetic and charged stripes is analyzed, including effects of long-range Coulomb repulsion. Remarkably, down to the limit of two-cell wide stripes, the dispersion can be interpreted as essentially a superposition of the two end-phase dispersions, with superposed minigaps associated with the lattice periodicity. The largest minigap falls near the Fermi level; it can be enhanced by proximity to a (bulk) Van Hove singularity. The calculated spectra are …
Dispersion Anomalies Induced By The Low-Energy Plasmon In The Cuprates, R. S. Markiewicz, A. Bansil
Dispersion Anomalies Induced By The Low-Energy Plasmon In The Cuprates, R. S. Markiewicz, A. Bansil
Robert Markiewicz
We discuss the characteristic effects of the electron plasmon interaction resulting from the ~ 1 eV plasmon, which is a universal feature in the cuprates. Using the framework of a one-band tight binding model, we identify signatures of this low energy plasmon in the electronic structure of metallic overdoped Bi₂212 as well as half-filled insulating SCOC. The electron-plasmon interaction is found to yield renormalizations near the Fermi energy in reasonable accord with experimental observations, and to produce dispersion anomalies at higher energies.
Berryonic Matter In The Cuprates, R. S. Markiewicz
Berryonic Matter In The Cuprates, R. S. Markiewicz
Robert Markiewicz
A novel form of Jahn-Teller (JT) effect in the cuprates can be reinterpreted as a conventional JT effect on a lattice with a larger unit cell. There is a triplet of instabilities, parametrized by a pseudospin, consisting of a form of the low-temperature tetragonal phase, a charge density wave phase, and a flux phase (orbital antiferromagnet). On a single 4-Cu plaquette, the problem is of E ⊗ (b1 + b2) form. For a special choice of parameters, the model supports a dynamic JT effect, but is classically chaotic. The connection of this phase with Berryonic matter is discussed.