scholarly journals Collective spin fluctuation mode and Raman scattering in superconducting cuprates

2000 ◽  
Vol 62 (22) ◽  
pp. 15204-15207 ◽  
Author(s):  
F. Venturini ◽  
U. Michelucci ◽  
T. P. Devereaux ◽  
A. P. Kampf
Keyword(s):  
Raman Scattering ◽  
Spin Fluctuation ◽  
Superconducting Cuprates ◽  
Fluctuation Mode

scholarly journals Electronic Raman scattering in superconducting cuprates

1999 ◽  
Vol 112 (4) ◽  
pp. 183-188 ◽  
Author(s):  
A.V. Chubukov ◽  
D.K. Morr ◽  
G. Blumberg
Keyword(s):  
Raman Scattering ◽  
Superconducting Cuprates ◽  
Electronic Raman Scattering

scholarly journals Silver route to cuprate analogs

2019 ◽  
Vol 116 (5) ◽  
pp. 1495-1500 ◽  
Author(s):  
Jakub Gawraczyński ◽  
Dominik Kurzydłowski ◽  
Russell A. Ewings ◽  
Subrahmanyam Bandaru ◽  
Wojciech Gadomski ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Neutron Scattering ◽  
Inelastic Neutron Scattering ◽  
Parent Compound ◽  
Mott Insulator ◽  
Inelastic Neutron ◽  
Square Lattice ◽  
Antiferromagnetic Coupling ◽  
Superconducting Cuprates ◽  
Electronic Parameters

The parent compound of high-Tc superconducting cuprates is a unique Mott insulator consisting of layers of spin-12 ions forming a square lattice and with a record high in-plane antiferromagnetic coupling. Compounds with similar characteristics have long been searched for without success. Here, we use a combination of experimental and theoretical tools to show that commercial AgF2 is an excellent cuprate analog with remarkably similar electronic parameters to La2CuO4 but larger buckling of planes. Two-magnon Raman scattering and inelastic neutron scattering reveal a superexchange constant reaching 70% of that of a typical cuprate. We argue that structures that reduce or eliminate the buckling of the AgF2 planes could have an antiferromagnetic coupling that matches or surpasses the cuprates.

Extended Van Hove Singularity in Raman Spectra of High-Tc Superconductors

1998 ◽  
Vol 12 (24) ◽  
pp. 2455-2473 ◽  
Author(s):  
O. V. Misochko ◽  
E. Ya. Sherman
Keyword(s):  
Experimental Data ◽  
Raman Scattering ◽  
Raman Spectra ◽  
Brillouin Zone ◽  
Van Hove Singularity ◽  
High Tc Superconductors ◽  
High Tc ◽  
Superconducting Cuprates ◽  
Different Parts

We consider theoretically and experimentally how an extended van Hove singularity manifests itself in electronic and phonon Raman scattering in superconducting cuprates. Our analysis and experimental data shows that in the case of singularity carriers redistribution between different parts of the Brillouin zone and/or electronic bands is a common feature of both the electronic and phonon Raman scattering.

RAMAN SCATTERING STUDY OF TEMPERATURE- AND FIELD-DEPENDENT MAGNETIC POLARON FORMATION IN (Eu,Gd)O

2002 ◽  
Vol 16 (20n22) ◽  
pp. 3364-3367 ◽  
Author(s):  
H. RHO ◽  
C. S. SNOW ◽  
S. L. COOPER ◽  
Z. FISK ◽  
A. COMMENT ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Disordered Systems ◽  
Spin Fluctuation ◽  
Ferromagnetic Phase ◽  
Magnetic Polaron ◽  
Two Phase ◽  
Magnetic Polarons ◽  
System A ◽  
Carrier Interaction ◽  
Spin Carrier

We use Raman scattering to investigate magnetic polarons and spin-carrier interaction effects in the (Eu,Gd)O system. Raman scattering studies reveal great richness in the phase behavior of this system: a spin-fluctuation-dominated paramagnetic (PM) phase regime for T > T* > TC, a two-phase regime for T < T* in which magnetic polarons develop below T* and coexist with a remnant of the PM phase, and an inhomogeneous ferromagnetic phase regime for T < TC. We will discuss how these phase regimes evolve as functions of magnetic field, temperature, and Gd-substitution, and will compare the results with less disordered systems such as EuB6.

scholarly journals THEORY OF HIGH-Tc SUPERCONDUCTING CUPRATES BASED ON EXPERIMENTAL EVIDENCE

1999 ◽  
Vol 13 (29n31) ◽  
pp. 3405-3418 ◽  
Author(s):  
A. A. ABRIKOSOV
Keyword(s):  
Order Parameter ◽  
Short Range ◽  
Inelastic Neutron Scattering ◽  
Positive Curvature ◽  
Spin Fluctuation ◽  
Upper Critical Field ◽  
Inelastic Neutron ◽  
High Tc ◽  
Superconducting Cuprates ◽  
Short Range Repulsion

A model of superconductivity in layered high-temperature superconducting cuprates is proposed, based on the extended saddle point singularities in the electron spectrum, weak screening of the Coulomb interaction and phonon-mediated interaction between electrons plus a small short-range repulsion of Hund's, or spin-fluctuation, origin. This permits to explain the large values of T c , features of the isotope effect on oxygen and copper, the existence of two types of the order parameter, the peak in the inelastic neutron scattering, the positive curvature of the upper critical field, as function of temperature etc.

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