scholarly journals Gap anisotropy and universal pairing scale in a spin-fluctuation model of cuprate superconductors

2008 ◽  
Vol 78 (22) ◽  
Author(s):  
Ar. Abanov ◽  
A. V. Chubukov ◽  
M. R. Norman
Keyword(s):  
Cuprate Superconductors ◽  
Spin Fluctuation ◽  
Gap Anisotropy ◽  
Fluctuation Model

MAGNETIC PROPERTIES OF U1-xDyxAlyNi5-y (y=0,1) SYSTEMS

2003 ◽  
Vol 17 (27n28) ◽  
pp. 1453-1460
Author(s):  
ILEANA LUPSA
Keyword(s):  
Magnetic Properties ◽  
Low Temperature ◽  
Spin Fluctuation ◽  
Magnetic Moments ◽  
Transition Temperatures ◽  
Temperature Range ◽  
Fluctuation Model ◽  
Magnetically Ordered

The magnetic properties of U 1-x Dy x Al y Ni 5-y (y=0,1) systems were investigated in the 2(5)–600 K temperature range and for fields up to 80 kOe. The systems having x≥0.2 are magnetically ordered with low transition temperatures and magnetization mainly due to the Dy contribution. The nickel exhibits magnetic moments, very weak in the low temperature range and well-defined effective moments over transition temperatures. The nickel behavior is discussed in terms of the spin fluctuation model.

METAMAGNETISM AND SPIN FLUCTUATIONS IN Co-BASED INTERMETALLIC COMPOUNDS

1993 ◽  
Vol 07 (01n03) ◽  
pp. 788-793 ◽  
Author(s):  
TSUNEAKI GOTO ◽  
TOSHIRO SAKAKIBARA
Keyword(s):  
Ground State ◽  
High Field ◽  
Spin Fluctuation ◽  
Spin Fluctuations ◽  
Itinerant Electron ◽  
Metamagnetic Transition ◽  
Paramagnetic Region ◽  
High Field Magnetization ◽  
Transition Field ◽  
Fluctuation Model

High field magnetization and susceptibility of Co-based compounds Y(Co1−xA1x)2 are investigated in the paramagnetic region 0≤x≤0.11. In all the region, a sharp metamagnetic transition is observed, while the susceptibility shows a maximum at finite temperature Tmax. The transition field Hc exhibits a positive shift proportional to T2 with temperature. The Hc in the ground state is found to be proportional to Tmax. The experimental results are discussed with a new theory for itinerant electron metamagnetism based on the spin fluctuation model.

ELECTRONIC THEORY FOR ELECTRON-DOPED CUPRATE SUPERCONDUCTORS: d-WAVE SUPERCONDUCTIVITY AND THE PHASE DIAGRAM

2000 ◽  
Vol 14 (29n31) ◽  
pp. 3555-3560
Author(s):  
D. MANSKE ◽  
I. EREMIN ◽  
K. H. BENNEMANN
Keyword(s):  
Cuprate Superconductors ◽  
Narrow Range ◽  
Spin Fluctuation ◽  
Flat Band ◽  
Superconducting Transition ◽  
Phonon Interaction ◽  
Pairing Mechanism ◽  
Lattice Disorder ◽  
Electron Phonon Interaction ◽  
The One

Using the one-band Hubbard Hamiltonian we determine various basic properties of the electron-doped cuprate superconductor Nd 2-x Ce x CuO 4 for a spin-fluctuation-induced pairing mechanism. We find a narrow range of superconductivity and, most importantly, like for hole-doped cuprates dx2-y2 -symmetry for the superconducting order parameter. The superconducting transition temperatures Tc(x) for various electron doping concentrations x are calculated to be much smaller than for hole-doped cuprates due to the different energy dispersion and a flat band well below the Fermi level. We find that lattice disorder may sensitively distort the dx2-y2 -symmetry via electron-phonon interaction yielding a finite isotope exponent α0.

Raman electronic continuum in a spin-fluctuation model for superconductivity

1995 ◽  
Vol 52 (1) ◽  
pp. 603-614 ◽  
Author(s):  
D. Branch ◽  
J. P. Carbotte
Keyword(s):  
Spin Fluctuation ◽  
Fluctuation Model

scholarly journals Thermodynamics of itinerant magnets in a classical spin-fluctuation model

2008 ◽  
Vol 78 (18) ◽  
Author(s):  
A. L. Wysocki ◽  
J. K. Glasbrenner ◽  
K. D. Belashchenko
Keyword(s):  
Spin Fluctuation ◽  
Classical Spin ◽  
Fluctuation Model

Anisotropic Superfluidity inHe3: Consequences of the Spin-Fluctuation Model

1973 ◽  
Vol 8 (5) ◽  
pp. 2732-2734 ◽  
Author(s):  
W. F. Brinkman ◽  
P. W. Anderson
Keyword(s):  
Spin Fluctuation ◽  
Fluctuation Model

scholarly journals Unusual symmetries of the order parameter in cuprates

2020 ◽  
Vol 2 (4) ◽  
pp. 207-212
Author(s):  
Tran Van Luong ◽  
Nguyen Thi Ngoc Nu
Keyword(s):  
High Temperature ◽  
Order Parameter ◽  
Cuprate Superconductors ◽  
High Temperature Superconductivity ◽  
Spin Fluctuation ◽  
High Temperature Superconductors ◽  
Coulomb Repulsion ◽  
Bcs Theory ◽  
S Wave ◽  
Wave Symmetry

The BCS superconducting theory, introduced by J. Bardeen, L. Cooper and R. Schriffer in 1957, succeeded in describing and satis-factorily explaining the nature of superconductivity for low-temperature superconductors. However, the BCS theory cannot explain the properties of high-temperature superconductors, discovered by J. G. Bednorz and K. A. Müller in 1986. Although scientists have found a lot of new superconductors and their transition temperatures are constantly increasing, most high-temperature superconductors are found by experiment and so far no theory can fully explain their properties. Many previous studies have suggested that the order parameter in high-temperature copper-based superconductors (cuprate superconductors - cuprates) is in the form of d-wave symmetry, but recent results show that the order parameter has an extended s-wave symmetry (extended s wave). Studying the symmetric forms of order parameters in cuprate can contribute to understanding the nature of high-temperature superconductivity. In this article, the authors present an overview of the development of high-temperature supercon-ductors over the past 30 years and explains unusual symmetries of the order parameter in copper-based superconductors. The com-petition of three coupling mechanisms of electrons in cuprates (the mechanism of coupling through coulomb repulsion, electron-phonon mechanism and spin-fluctuation mechanism) affects the unusual symmetry of the order parameter. The solution of the self-consistency equation in simple cases has been found and the ability to move the phase within the superconducting state has been shown.

The heat capacity of liquid 3He beyond T3 log T

1987 ◽  
Vol 65 (11) ◽  
pp. 1549-1551
Author(s):  
A. M. J. Schakel ◽  
Ch. J. Calkoen ◽  
Ch. G. van Weert
Keyword(s):  
Heat Capacity ◽  
Magnetic Susceptibility ◽  
Temperature Dependence ◽  
Analytic Functions ◽  
Spin Fluctuation ◽  
Landau Theory ◽  
Particle Mass ◽  
Fermi Liquids ◽  
Quasi Particle ◽  
Fluctuation Model

The heat capacity of liquid 3He up to 2.5 K is calculated on the basis of a spin-fluctuation model in the context of the Landau theory of Fermi liquids. A good fit of the data is achieved by including the temperature dependence of the magnetic susceptibility and by using a different, smaller, quasi-particle mass. It is also shown that the magnetic susceptibility and the compressibility are analytic functions of the temperature.

Sign in / Sign up

Export Citation Format

Share Document