We introduce various exchange interactions in a model Hamiltonian for Ce3+ ions in cubic symmetry with three configurations (f0,f1,f2). With the impurity pseudo spin SI = 1/2, our Hamiltonian includes: (i) One-channel Sc = 1/2 Anderson model; (ii) Two-channel Sc = 1/2 Anderson model; (iii) An unforseen one-channel Sc = 3/2 Anderson model with a non-trivial fixed point; (iv) Mixing exchange inte...

We have found ferromagnetism in epitaxially grown superlattices of CaRuO(3)/CaMnO(3) that arises in one unit cell at the interface. Scanning transmission electron microscopy and electron energy loss spectroscopy indicate that the difference in magnitude of the Mn valence states between the center of the CaMnO(3) layer and the interface region is consistent with double exchange interaction among...

In this paper we consider two different geometry of quasi one-dimensional semiconductors and calculate their exchange-correlation induced bandgap renormalization (BGR) as a function of the electron-hole plasma density and quantum wire width. Based on different fabrication scheme, we define suitable external confinement potential and then leading-order GW dynamical screening approximation is use...

Exchange interaction is responsible for both covalent bonding and ferromagnetism in both localized and itinerant electron systems. Nevertheless, crystalline structures are not apparently affected by a change of electron magnetic state in most systems. In these systems, the exchange coupling constant J can be treated as constant to the first order during a magnetic transition. Coupling between t...

We study the competition between the exchange and the direct Coulomb interaction near the edge of a two-dimensional electron gas in a strong magnetic field using density-functional theory in a local approximation for the exchange-energy functional. Exchange is shown to play a significant role in reducing the spatial extent of the compressible edge channel regions obtained from an electrostatic ...

Spin exchange between a single-electron charged quantum dot and itinerant electrons leads to an emergence of Kondo correlations. When the quantum dot is driven resonantly by weak laser light, the resulting emission spectrum allows for a direct probe of these correlations. In the opposite limit of vanishing exchange interaction and strong laser drive, the quantum dot exhibits coherent oscillatio...

We investigate the effect of strong electron-electron repulsion on the electronphonon interaction from a Fermi-liquid point of view. In particular we show that the strong interaction is responsible for vertex corrections, which are strongly dependent on the vF q/ω ratio, where vF is the Fermi velocity and q and ω are the transferred momentum and frequency respectively. These corrections generic...

The most widely-used density functionals for the exchange-correlation energy are inexact for one-electron systems. Their self-interaction errors can be severe in some applications. The problem is not only to correct the self-interaction error, but to do so in a way that will not violate size-consistency and will not go outside the standard Kohn-Sham density functional theory. The solution via t...

The antiferromagnetic ground state of the half-filled Hubbard model with the doubly degenerate orbital has been studied by using the slave-boson mean-field theory which was previously proposed by the present author. Numerical calculations for the simple cubic model have shown that the metal-insulator transition does not take place except at the vanishing interaction point, in strong contrast wi...

The antiferromagnetic ground state of the half-filled Hubbard model with the doubly degenerate orbital has been studied by using the slave-boson mean-field theory which was previously proposed by the present author. Numerical calculations for the simple cubic model have shown that the metal-insulator transition does not take place except at the vanishing interaction point, in strong contrast wi...