Sökning: "exchange interactions"

Visar resultat 16 - 20 av 257 avhandlingar innehållade orden exchange interactions.

1. 16. Complex patterns : from physical to social interactions

   Författare :Andreas Grönlund; Petter Minnhagen; Hawoong Jeong; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Complex networks; collective dynamics; statistical physics; random graphs; Statistical physics; Statistisk fysik;

   Sammanfattning : Interactions are what gives us the knowledge of the world around us. Interactions on all levels may fundamentally be seen as an exchange of information and a possible response of the same. Whether it is an electron in an electrical field or a handsome dude in a bar responding to a flirtation---interactions make things happen. LÄS MER

3. 17. Density Functional Theory Applied to Materials for Spintronics

   Författare :Diana Mihaela Iusan; Olle Eriksson; Biplab Sanyal; Hiroshi Katayama-Yoshida; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; spintronics; dilute magnetic semiconductors; density functional theory; exchange interactions; magnetic percolation; ordering temperature; disorder; electronic structure; Physics; Fysik; Materialvetenskap; Materials Science;

   Sammanfattning : The properties of dilute magnetic semiconductors have been studied by combined ab initio, Monte Carlo, and experimental techniques. This class of materials could be very important for future spintronic devices, that offer enriched functionality by making use of both the spin and the charge of the electrons. LÄS MER

4. 18. Quantum chromodynamics and colour singlet exchange in high energy interactions

   Författare :Rikard Enberg; Gunnar Ingelman; W. James Stirling; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; Fysik; Physics; Fysik; Fysik; Physics;

   Sammanfattning : Quantum chromodynamics (QCD) is the fundamental theory in elementary particle physics that describes the strong interaction in terms of exchanges of force-carrying, colour-charged particles known as gluons. Although well-established through experimental verifications, there are fundamental unsolved problems in the theory. LÄS MER

5. 19. The colour of gluon interactions : Studies of Quantum Chromodynamics in soft and hard processes

   Författare :Nicuşor Tîmneanu; Jochen Bartels; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; Fysik; Physics; Fysik; Fysik; Physics;

   Sammanfattning : Quantum Chromodynamics (QCD) is the theory of the strong interaction, one of the fundamental forces of nature. The interactions between quarks are mediated by gluons, which are the colour-charged gauge fields in QCD. LÄS MER

7. 20. Nonlocal Correlations in Density Functional Theory

   Författare :Henrik Rydberg; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; bonding; GGA; adhesion; graphene; DFT; exchange; adsorption; LDA; first principles; polarization; vdW; determinants; correlation; graphite; surface states; van der Waals; density-functional theory; physisorption; nonlocal; functional;

   Sammanfattning : In Density Functional Theory, the widely used local and semilocal approximations to the exchange-correlation energy, the local density approximation (LDA) and the generalized gradient approximations (GGAs), lack a physical description of truly nonlocal correlation effects, which are absolutely essential for a proper description of soft matter. A scheme is proposed that provides a basis for systematic improvements beyond LDA and GGA, including correlations at intermediate and long range, giving rise to bonds of pure van der Waals type as well as more intricate, intermediate-range correlation bonds. LÄS MER