Spin-based electronics

One such quantum property of the electron is its spin, i.e., its magnetism. Devices that rely on an electron s spin to perform their functions form the foundation of spintronics (short for spin-based electronics), also defined as magneto-electronics. Information-processing teclmology has thus far relied on purely charge-based devices, ranging from the now outdated vacuum tube to today s million-transistor microchips. The conventional electronic... 

Semiconductor nanoparticles and QDs are widely used in various fields such as luminescent biolabels [150-152] and have been demonstrated as components in regenerative solar cells [153-155], optical gain devices [24] and electroluminescent devices [23, 156, 157]. DMS have applications in spin-based electronics technologies, or spintronics [158-161]. Spintronic devices such as magnetic-optic switches, magnetic sensors, spin valve transistors and spin LEDs can be activated by implanting ferromagnetic Mn, Ni, Co and Cr in semiconductors [162-165]. Some of the applications of semiconductor nanoparticles or QDs have been explained in this section. 

Wolf SA, Awschalom DD, Buhrman RA, Daughton JM, Molnar S, Roukes ML, Chtchelkanova AY, Treger DM. Spintronics a spin-based electronics vision for the future. Science 2001 294 1484-88. 

A significant number of Ir111 complexes arise from the oxidative addition reactions of Ir1 species. Such reactions may proceed via routine addition, whereas some proceed by ligand expulsion in conjunction with oxidative addition. Complexes containing Ir111 have a low-spin d6 electronic configuration, and are usually to be found with an octahedral-based ligand set. 

The first term in (3.20) describes the interaction of the oscillating rf field with the electron spin, and contributes only in a first (or higher) order spin base to the nuclear transition probability. For a single nucleus, the first order transition probability is given45 by... 

The Pauli exclusion principle states that no more than two electrons may occupy the same orbital, and they must have opposite spins. Based on this principle, 2n is the maximum number of electrons compatible with a given level. 

Electron-pair donor (or Lewis base), NUCLEOPHILE ELECTRON SINK ELECTRON SPIN RESONANCE ELECTRON TRANSEER MARCUS EQUATION ELECTRODE KINETICS Electron transfer mechanism,... 

Recently, an alternative scheme based on singlet-type strongly orthogonal geminals (SSG) was proposed [5]. In this scheme, the wavefunction is split into gem-inal subspaces depending on the number of spin-up or spin-down electrons, n and n, respectively, while the wavefunction is filled up with one Slater determinant. 

The weaknesses of the EHM are due largely to its neglect of electron spin and electron-electron repulsion and the fact that it bases the energy of a molecule simply on the sum of the one-electron energies of the occupied orbitals, which ignores electron-electron repulsion and intemuclear repulsion this is at least partly the reason it usually gives poor geometries. 

Another possibility to address the problem of the correlation crystal fields is an approach based on different wavefunctions for the spin-up and spin-down electrons. This spin-correlated crystal-field model merely doubles the number of crystal-field parameters and thus can be applied in most cases. Shen and Holzapfel (1995c) presented a high pressure study on spin-correlated crystal fields in MFCl Sm2+ (M = Ba, Sr, Ca). In particular, they considered the splitting ratio R of the 5Di and 7Fi multiplets, which should be equal to 0.298 within the conventional one-electron crystal-field theory and independent of the host crystal. In a first step, Shen and Holzapfel (1995c) considered ambient pressure as well as high pressure data of the isoelectronic Eu3+ ion. In this case they found a ratio of R = 0.238, which could be explained by taking into account a spin-correlated crystal-field parameter C2 = —0.007(3). 

Abstract Understanding the origin of chirality in nature has been an active area of research since the time of Pasteur. In this chapter we examine one possible route by which this asymmetry could have arisen, namely chiral-specific chemistry induced by spin-polarized electrons. The various sources of spin-polarized electrons (parity violation, photoemission, and secondary processes) are discussed. Experiments aimed at exploring these interactions are reviewed starting with those based on the Vester-Ulbricht hypothesis through recent studies of spin polarized secondary electrons from a magnetic substrate. We will conclude with a discussion of possible new avenues of research that could impact this area. 

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