Increase of effective exchange energy due to phonon mediated interaction in the extended t-J model

2012 ◽  
Author(s):  
N. S. Mondal ◽  
N. K. Ghosh
Keyword(s):  
Exchange Energy ◽  
Effective Exchange

Exchange Splitting of Electron Spins in Copper-Based Kondo Alloys

1972 ◽  
Vol 50 (17) ◽  
pp. 1999-2011 ◽  
Author(s):  
P. T. Coleridge ◽  
G. B. Scott ◽  
I. M. Templeton
Keyword(s):  
Bound States ◽  
Zeeman Splitting ◽  
Solute Concentration ◽  
Exchange Energy ◽  
Spin Splitting ◽  
Electron Spins ◽  
Conduction Electrons ◽  
Scattering Effects ◽  
Effective Exchange ◽  
Cr System

Modification of the Zeeman splitting of conduction-electron spins by an s–d exchange interaction has been studied in the de Haas – van Alphen effect at fields up to 50 kG and temperatures of order 1 K in very dilute copper-based alloys of Cr, Mn, Fe, and Co. In Cu(Cr) there is a linear relationship between an effective exchange energy and solute concentration, and the results indicate an antiferromagnetic interaction between conduction electrons and polarized impurity spins with very little Kondo screening. The effects of increasing field or decreasing temperature are consistent with a simple polarization of the impurity spins. The variation of the exchange energy from orbit to orbit is explained by the variation over the copper Fermi surface of the d-like part of the wave function. The occurrence of clean spin-splitting zeros in the Cu(Cr) system is believed to be a fortuitous result of a symmetrical positioning of the Friedel virtual bound states relative to the Fermi energy. In Cu(Mn) the exchange energy effects are similar to those in Cu(Cr) but involve also a differential scattering of the two spin components in the de Haas – van Alphen oscillations which results in spin-splitting minima rather than zeros. In Cu(Fe) and Cu(Co) differential scattering effects are also observed, but in Cu(Fe) the exchange energy is markedly reduced and in Cu(Co) it is almost completely eliminated by spin compensation of the impurity moment by conduction electrons.

Calculation of exchange energy in quantum dots : application to porous silicon

1993 ◽  
Vol 03 (C5) ◽  
pp. 355-358 ◽  
Author(s):  
G. FISHMAN ◽  
R. ROMESTAIN ◽  
J. C. VIAL
Keyword(s):  
Quantum Dots ◽  
Porous Silicon ◽  
Exchange Energy

Regional effects of inflation targeting in Russia: Factors of heterogeneity and structural inflation rates

2019 ◽  
pp. 70-89
Author(s):  
Michael I. Zhemkov
Keyword(s):  
Monetary Policy ◽  
Inflation Targeting ◽  
Structural Factors ◽  
Regional Effects ◽  
Inflation Rates ◽  
Price Growth ◽  
Effective Exchange ◽  
The Difference ◽  
Communication Policies ◽  
Structural Levels

Inflation targeting in Russia implies maintaining stable low inflation at a level of 4% throughout the country. The presence of structural factors in some regions can determine deviations from the all-Russian inflation, which can lead to different effects of monetary policy in Russian regions. In this paper, we analyze regional heterogeneity of inflation and factors of inflation deviations from the national average, estimate structural levels of inflation in the regions of Russian Federation. These estimates confirm the presence of some regional factors of inflation deviations from the all-Russian indicator, such as the difference in productivity growth of the tradable and non-tradable sectors (Balassa—Samuelson effect), effective exchange rates, real incomes and product stocks. In addition, our results confirm the presence of regions with price growth rate above and below monetary policy target. The results of this research can be used for the development of monetary and communication policies.

POTENTIAL PRODUCTIVITY ADAPTIVE AGROPHUTOCENOZIS ON SLOPING LANDS OF THE STEPPE TRANS-URALS

2020 ◽  
Author(s):  
R.А. Idrisov ◽  
Keyword(s):  
Protein C ◽  
Nutritional Value ◽  
Energy Content ◽  
Single Species ◽  
Exchange Energy ◽  
Metabolic Energy ◽  
Potential Productivity ◽  
Maximum Productivity ◽  
Sloping Lands ◽  
Natural Herb

The correct construction of agrophytocenoses on the slopes of the steppe trans-Urals helped to create maximum productivity. In the arid climate, the most productive were the double mixtures of alfalfa with brittle sitnik, wheatgrass is syd, providing an average of 41.6 and 40.2 quintals per hectare (c/ha) of hay, 32.1 and 31.0 GJ/ha OE (exchange energy per hectare), 4.5 and 4.3 quintals per hectare of boiled protein (c/ha) over 5 years. Single-species steppe ecotypes, brittle sieve and wheatgrass sieve in productivity slightly gave way to double components, providing respectively hay- 32.2 and 37.2 cents per hectare, exchange energy 22.2 and 25.7 GJ/ha, digested protein 1.93 and 2.53 c/ha. The enrichment of agrophytocense by the legume component allowed to increase the metabolic energy content to the level of 32.1 and 31.0-GJ/ha, digested protein to 4.5 and 4.3 quintals per hectare, which is 14 times the nutritional value of the metabolic energy, the digested protein is 10 times higher than the natural herb.

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