Spin exchange energy for a pair of valence band holes in artificial molecules

2014 ◽  
Vol 29 (11) ◽  
pp. 115022 ◽  
Author(s):  
W J Pasek ◽  
B Szafran ◽  
M P Nowak
Keyword(s):  
Valence Band ◽  
Spin Exchange ◽  
Exchange Energy

scholarly journals The Microscopic Mechanisms Involved in Superexchange

2021 ◽  
Vol 8 (1) ◽  
pp. 6
Author(s):  
Jacques Curély
Keyword(s):  
Crystal Field ◽  
Physical Interpretation ◽  
Exchange Coupling ◽  
Spin Exchange ◽  
Closed Shell ◽  
Exchange Energy ◽  
Heisenberg Spin ◽  
Field Magnitude ◽  
M 10 ◽  
Molecular Integrals

In earlier work, we previously established a formalism that allows to express the exchange energy J vs. fundamental molecular integrals without crystal field, for a fragment A–X–B, where A and B are 3d1 ions and X is a closed-shell diamagnetic ligand. In this article, we recall this formalism and give a physical interpretation: we may rigorously predict the ferromagnetic (J < 0) or antiferromagnetic (J > 0) character of the isotropic (Heisenberg) spin-spin exchange coupling. We generalize our results to ndm ions (3 £ n £ 5, 1 £ m £ 10). By introducing a crystal field we show that, starting from an isotropic (Heisenberg) exchange coupling when there is no crystal field, the appearance of a crystal field induces an anisotropy of exchange coupling, thus leading to a z-z (Ising-like) coupling or a x-y one. Finally, we discuss the effects of a weak crystal field magnitude (3d ions) compared to a stronger (4d ions) and even stronger one (5d ions). In the last step, we are then able to write the corresponding Hamiltonian exchange as a spin-spin one.

Optically tunable spin-exchange energy at donor:acceptor interfaces in organic solar cells

2014 ◽  
Vol 105 (2) ◽  
pp. 023302 ◽  
Author(s):  
Mingxing Li ◽  
Hongfeng Wang ◽  
Lei He ◽  
Huidong Zang ◽  
Hengxing Xu ◽  
...  
Keyword(s):  
Solar Cells ◽  
Organic Solar Cells ◽  
Spin Exchange ◽  
Exchange Energy

Spin exchange, past, present and future

1985 ◽  
Vol 10 (6) ◽  
pp. 645-657 ◽  
Author(s):  
W. Happer
Keyword(s):  
Spin Exchange

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

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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