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George Kastrinakis

Publications and source records attributed to George Kastrinakis.

23 records · Page 2Linked to original sources
arXiv2001

A Fermi liquid model for the overdoped and optimally doped cuprate superconductors: scattering rate, susceptibility, spin resonance peak and superconducting transition

This paper treats a number of issues of the cuprates, ranging from the spin resonance peak and the linear one-particle scattering rate to the superconducting transition, in the frame of a Fermi liquid model. Recent ARPES expts. by Valla et al., Science vol. 285, 2110 (1999), and e-print cond-mat/0003407, directly support the linearity of the one-particle scattering rate everywhere in the Brillouin zone we obtained here. We show that the origin of this linearity is the strong linear in energy term of the imaginary part of the carrier susceptibility. This result yields directly a linear in temperature resistivity and linear in 1/energy optical conductivity. We show that the low energy dependence of the susceptibility can have a purely fermionic origin. We introduce an antiferromagnetic ansatz for the susceptibility of the carriers.Inter alia, this ansatz may explain the appearance of the spin resonance peak (observed in neutron scattering) in the normal state of the cuprates. Further, we obtain particularly high transition temperatures $T_c$ from our Eliashberg scheme by using this ansatz: we have a $d_{x^2-y^2}$ gap with $T_c > 120 ^o$K for nearest neighbour hopping $t=250meV$.

cond-mat.str-el↗
arXiv1997

Paramagnons, weak disorder and positive giant magnetoresistance

At low temperature and for finite spin scattering in a weakly disordered metal, for a certain value, predicted from our theory, of the material-dependent paramagnon interaction, the total conductivity becomes highly sensitive to the orbital effects of a finite magnetic field. As a consequence, positive giant magnetoresistance and giant corrections to the Hall coefficient arise. We obtain very good agreement between this theory and recent positive giant magnetoresistance experiments, while making specific material-dependent predictions.

cond-mat.dis-nn↗
arXiv1997

An unconventional Fermi liquid model for the optimally doped and overdoped cuprate superconductors

Based on an unconventional Fermi liquid model, we present several results on the optimally doped and overdoped cuprate superconductors. For the normal state, we provide an analytic demonstration, backed by self-consistent Baym-Kadanoff (BK) numerical calculations, of the linear in $T$ resistivity and linear in 1/$ε$ optical conductivity, provided the interacting Fermi liquid has strong peaks in its density of states (van-Hove singularities in 2 dimensions) near the chemical potential $μ$. Moreover, we find that the interactions tend to pin these strong density of states peaks close to $μ$. We show that the low energy dependence of $χ_{MMP}$ has a fermionic origin. We obtain particularly high transition temperatures $T_c$ from our BK-Eliashberg scheme by introducing an ansatz for the fermionic susceptibility of the carriers. We postulate that the latter is enhanced in an additive manner due to the weak antiferromagnetic order of the CuO$_2$ planes. We have obtained a $d_{x^2-y^2}$ gap with $T_c > 120 ^o$K for n.n. hopping $t=250meV$.

cond-mat.supr-con↗
arXiv1996

On the Normal State of the High Temperature Superconductors

Based on a Fermi liquid model, we present several results on the normal state of the optimally doped and overdoped cuprate superconductors. Our main result is an analytic demonstration, backed by self-consistent numerical calculations, of the linear in temperature resistivity and linear in 1/(energy) optical conductivity, provided the interacting Fermi liquid has strong peaks in its density of states (van-Hove singularities in 2 dimensions) near the chemical potential. Moreover, we find that the interactions tend to pin these strong peaks close to the chemical potential. This fact compares favorably with experiment on a variety of cuprates. Finally, we show that the above scenario yields naturally the low energy dependence of the experimentally determined susceptibility, without reference to spin waves.

cond-mat↗