We study integrable models for electrons in metals when the single particle spectrum is discrete. The electron-electron interactions are BCS-like pairing, Coulomb repulsion, and spin exchange coupling. These couplings are, in general, nonuniform in the sense that they depend on the levels occupied by the interacting electrons. By using the realization of spin 1/2-operators in terms of electrons...

In quantum theory Hamilton operators with spininteractions have a long history [1 – 5]. Triple spin interaction have been studied by several authors [6 – 19]. Iglói [6] investigated an Ising model with three-spin interaction by finite-size scaling and applying free boundary conditions. Vanderzande and Iglói [7] studied the critical behaviour and logarithmic corrections of a quantum model with t...

In semiconductor spintronics, electron spin rather than charge is the key property. This paper describes several spin-related devices using spin-orbit interaction. We have experimentally confirmed that the spin-orbit interaction in a semiconductor two-dimensional electron gas channel can be controlled by a gate voltage. This is the first step towards the creation of functional spin devices. The...

The effect of spin-orbit interaction on persistent currents in mesoscopic Hubbard rings threaded by an Aharonov-Bohm flux is investigated putting stress on the orbital magnetism. The non-perturbative treatment of the spin-orbit interaction developed by Meir et al. is combined with the Bethe ansatz solution to deal with this problem exactly. We find that the interplay of spin-orbit interaction a...

We investigate interactions between spins of strongly correlated electrons subject to the spin-orbit interaction. Our main finding is that of a novel, spin-orbit mediated anisotropic spin-spin coupling of the van der Waals type. Unlike the standard exchange, this interaction does not require the wave functions to overlap. We argue that this ferromagnetic interaction is important in the Wigner c...

The collective properties of spin-crossover chains are studied. Spin-crossover compounds contain ions with a low-spin ground state and low lying high-spin excited states and are of interest for molecular memory applications. Some of them naturally form one-dimensional chains. Elastic interaction and Ising exchange interaction are taken into account. The transfer-matrix approach is used to calcu...

We use gate voltage control of the exchange interaction to prepare, manipulate, and measure two-electron spin states in a GaAs double quantum dot. By placing two electrons in a single dot at low temperatures we prepare the system in a spin singlet state. The spin singlet is spatially separated by transferring an electron to an adjacent dot. The spatially separated spin singlet state dephases in...

The spin-orbit interaction in semiconductors is shown to result in an anisotropic contribution into the exchange Hamiltonian of a pair of localized conduction-band electrons. The anisotropic exchange interaction exists in semiconductor structures which are not symmetric with respect to spatial inversion, for instance in bulk zinc-blend semiconductors. The interaction has both symmetric and anti...

A magnetoresistance (MR) effect induced by the Rashba spin-orbit interaction was predicted, but not yet observed, in bilayers consisting of normal metal and ferromagnetic insulator. We present an experimental observation of this new type of spin-orbit MR (SOMR) effect in the Cu[Pt]/Y3Fe5O12 (YIG) bilayer structure, where the Cu/YIG interface is decorated with nanosize Pt islands. This new MR is...