Related papers: Route to ferromagnetism in organic polymers
We consider the one-orbital $N$-site repulsive Hubbard model on two kagome-like chains, both of which yield a completely dispersionless (flat) one-electron band. Using exact many-electron ground states in the subspaces with $n\le n_{\max}$…
Conjugated polymers are soft, one-dimensional conductors that admit complex interactions between their polymeric, conformational degrees of freedom and their electronic ones. The presence of extended electronic states along their backbone…
We investigate the properties of many-electron systems in two-dimensional polygonal (triangle, square, pentagon, hexagon) potential wells by using the density functional theory. The development of the ground state electronic structure as a…
Half-metallic ferromagnets show 100% spin-polarization at the Fermi level and are ideal candidates for spintronic applications. Despite the extensive research in the field, very few materials have been discovered so far. Here we present…
A constant increase in the need of clean energy demands more innovation from the research community. Active and stable materials that can make use of the solar radiation to promote different reactions are the cornerstone of emerging…
Ferroelectricity (Valasek, J. Phys. Rev. 1921, 17, 475) - a spontaneous formation of electric polarisation - is a solid state phenomenon, usually, associated with ionic compounds or complex materials. Here we show that, atypically for…
In contrast to semiconductors doped with transition metal magnetic elements, which become ferromagnetic at temperatures below ~ 100K, semiconductors doped with non-magnetic ions (e.g. silicon doped with phosphorous) have not shown evidence…
Twisted two-dimensional structures open new possibilities in band structure engineering. At magic twist angles, flat bands emerge, which give a new drive to the field of strongly correlated physics. In twisted double bilayer graphene dual…
Interacting electrons in flat bands give rise to a variety of quantum phases. One fundamental aspect of such states is the ordering of the various flavours - such as spin or valley - that the electrons can undergo and the excitation…
Existence of ferromagnetism in bulk calcium compounds is discovered theoretically. First-principles calculations of calcium phosphide, calcium arsenide and calcium antimonide in the zinc-blende structure have been performed to show the…
Graphene and its multilayers have attracted considerable interest owing to the fourfold spin and valley degeneracy of their charge carriers, which enables the formation of a rich variety of broken-symmetry states and raises the prospect of…
The evolution of the role of lattice vibrations in the formation of the pseudogap state in strongly correlated electron systems has been investigated concerning changes in the electron-phonon coupling parameters and the concentration of…
In this review, we present recent works on materials whose common point is the presence of electronic bands of very low dispersion, called "flat bands", which are due to specific atomic order effects without electron interactions. These…
Ab-initio results for structural and electronic properties of NaCl-type FeN are presented in a framework of plane-wave and ultrasoft pseudopotentials. Competition among different magnetic ordering is examined. We find the ferromagnetic…
We analyze the energy band structure of a two-dimensional electron gas in a periodic magnetic field of a longitudinal antiferromagnet by considering a simple exactly solvable model. Two types of states appear: with a finite and…
The ferromagnetism of Au nanograins is analysed based on a two-dimensional itinerant lattice model with on-site Coulomb repulsion, many-body spin-orbit interactions, and holding two hybridized bands, one correlated and one uncorrelated.…
Graphene has attracted a great interest in material science due to its novel electronic structrues. Recently, magnetism discovered in graphene based systems opens the possibility of their spintronics application. This paper provides a…
The emergence of the field of spintronics brought half-metallic ferromagnets to the center of scientific research. A lot of interest was focused on newly created transition-metal pnictides (such as CrAs) and chalcogenides (such as CrTe) in…
The band structure and electronic properties in a series of vinylene-linked heterocyclic conducting polymers are investigated using density functional theory (DFT). In order to accurately calculate electronic band gaps, we utilize hybrid…
We present a new class of flat-band Hubbard models which have saturated ferromagnetic ground states at two distinct electron numbers for different values of parameters. The models are extensions of Tasaki's flat-band models.