It has been suggested that the enlarged spin susceptibility in topological insulators, described by Van Vleck's formalism, accounts for ferromagnetism of bismuth-antimony chalcogenides doped with transition metal impurities. In contrast, earlier studies HgTe and related systems pointed out interband analog Ruderman-Kittel-Kasuya-Yosida interaction (the Bloembergen-Rowland mechanism) leads to an...

Because of their long coherence times and potential for scalability, semiconductor quantum-dot spin qubits hold great promise quantum information processing. However, maintaining high connectivity between qubits, which favor linear arrays with nearest neighbor coupling, presents a challenge large-scale computing. In this work, we present evidence long-distance spin-chain-mediated superexchange ...

Isomers of Dy 2 O@C 88 and C @C show a strong variation in the type strength Dy?Dy superexchange interactions magnetization relaxation rate.

Quantum gates between spin qubits can be implemented leveraging the natural Heisenberg exchange interaction two electrons in contact with each other. This is controllable by electrically tailoring overlap electronic wavefunctions quantum dot systems, as long they occupy neighbouring dots. An alternative route exploration of superexchange - coupling remote spins mediated a third idle electron th...

Silver(II) compounds exhibit powerful oxidizing properties and strong magnetic superexchange, but most of them comprise fluoride ligands. AgSO4 is a rare fluorine-free salt Ag(II) which found some application in organic chemistry. Here, we report discovery new polymorph (β). The distinct nature the two polytypes established using powder X-ray diffraction, vibrational spectroscopy theoretical ca...

The stability of the charge-stacked structure vis-à-vis the charge-alternate structure in the half-doped manganites is studied with a model that includes electronic kinetic energy, onsite and intersite Coulomb interactions, the Jahn–Teller energy, and the antiferromagnetic superexchange between the manganese core spins. It is shown that for a single zigzag chain, the electronic kinetic energy s...

Although the magnetoelectric effects - the mutual control of electric polarization by magnetic fields and magnetism by electric fields, have been intensively studied in a large number of inorganic compounds and heterostructures, they have been rarely observed in organic materials. Here we demonstrate magnetoelectric coupling in a metal-organic framework [(CH3)2NH2]Mn(HCOO)3 which exhibits an or...

We consider a superexchange Hamiltonian, H = -SUM ()(2S(i) . S(j)-(1/2)) (2T(i) . T(j)-(1/2)), which describes systems with orbital degeneracy and strong electron-phonon coupling in the limit of large on-site repulsion. In an SU(4) Schwinger boson representation, a reduced spin-orbital interaction is derived exactly, and a mean field theory has been developed. In one dimension, a spin-orbi...