High-temperature susceptibility of a Heisenberg ferromagnet using Green function theory

1968 ◽  
Vol 46 (12) ◽  
pp. 1502-1504 ◽  
Author(s):  
S. T. Dembinski
Keyword(s):  
High Temperature ◽  
Green Function ◽  
Random Phase Approximation ◽  
Function Theory ◽  
Random Phase ◽  
Heisenberg Ferromagnet ◽  
Zero Field ◽  
Phase Approximation ◽  
First Order ◽  
Temperature Susceptibility

A new first-order decoupling recently proposed, which gave very satisfactory results for the low-temperature magnetization of a Heisenberg [Formula: see text] ferromagnet, is used here to calculate the high-temperature zero-field susceptibility series. The results are close to those known from the random-phase-approximation decoupling.

On the Green-function theory of the spin- Heisenberg ferromagnet

1968 ◽  
Vol 46 (9) ◽  
pp. 1021-1028 ◽  
Author(s):  
S. T. Dembinski
Keyword(s):  
Green Function ◽  
Curie Temperature ◽  
Low Temperatures ◽  
Random Phase Approximation ◽  
Function Theory ◽  
Random Phase ◽  
Exact Result ◽  
Heisenberg Ferromagnet ◽  
First Order ◽  
The Green Function

A new first-order decoupling scheme for the Green function appearing in the theory of the spin-[Formula: see text] Heisenberg ferromagnet is introduced. At low temperatures the magnetization has no spurious term in T3 and the coefficient of the term in T4 is within a few percent of the Dyson exact result. The Curie temperature is equal to the random phase approximation Curie temperature.

The Curie temperature of a Heisenberg-Ising ferromagnet with uniaxial anisotropy

1982 ◽  
Vol 60 (3) ◽  
pp. 273-278 ◽  
Author(s):  
M. Tiwari ◽  
R. N. Srivastava
Keyword(s):  
Green Function ◽  
Curie Temperature ◽  
Random Phase Approximation ◽  
Random Phase ◽  
Uniaxial Anisotropy ◽  
Function Technique ◽  
Phase Approximation ◽  
Ising Ferromagnet ◽  
The Green Function

Effects of Ising anisotropy on Curie temperature have been studied in the presence of single ion anisotropy for a spin S = 1 system. The Green function technique with random phase approximation has been used taking into account all possible intersite correlations.

σ AND ω, WITH ∆-BARYON, AT HIGH TEMPERATURE

1996 ◽  
Vol 05 (03) ◽  
pp. 511-520
Author(s):  
ABHIJIT BHATTACHARYYA
Keyword(s):  
High Temperature ◽  
Temperature Dependence ◽  
Random Phase Approximation ◽  
Random Phase ◽  
Mean Field ◽  
Meson Mass ◽  
Phase Approximation ◽  
Effective Masses ◽  
The Mean ◽  
Walecka Model

The temperature dependence of σ and ω meson effective masses due to the presence of Δ-baryon has been studied. Starting from the Walecka model, containing both nucleon and Δ, the temperature dependence of effective masses of nucleon and Δ have been calculated at the Mean Field (MF) level. These results have been used to calculate the contribution to the effective masses of σ and ω from both [Formula: see text]- and [Formula: see text]-loops in Random Phase Approximation (RPA). The results are quite interesting. The σ-meson mass increases due to the [Formula: see text] loop whereas it decreases due to [Formula: see text]-loop with temperature. Further, the change in σ-meson mass due to [Formula: see text]-loop is much more compared to that due to [Formula: see text]-loop. For the ω-meson, both the loops are responsible for the increase in mass with temperature.

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