Magnetic photonic band-gap material at microwave frequencies based on ferromagnetic nanowires

We present an experimental investigation of a class of microwave photonic band-gap (PBG) materials, in which the magnetic permeability mu varies periodically within the material. This material is fabricated using a periodic arrangement of arrays of magnetic nanowires. As for dielectric or metallic PBG, the band-gap behavior varies with the geometrical parameters fixing the spatial periodicity of the magnetic structure. The magnetic photonic band gap is induced by the presence of a ferromagnetic resonance effect in the vicinity of the band gap. (C) 2003 American Institute of Physics

Influence of Elastic and Inelastic Electron-Phonon Interaction on Quantum Transport in Multigate Silicon Nanowire MOSFETs

This paper presents the effect of different elastic acoustic and inelastic optical electron-phonon interaction mechanisms on quantum transport and electrical characteristics of multigate silicon nanowire FETs. A 3-D quantum-mechanical device simulator based on the nonequilibrium Green's function formalism in the uncoupled mode space that can handle electron-phonon interactions has been developed to extract the physical parameters of the devices. The electron-phonon scattering has been treated by using the self-consistent Born approximation and deformation potential theory. Utilizing this simulator, we show that interaction of the carriers with optical phonons redistributes the energy and momentum of electrons in the transport direction, depending on the energy of the phonon. Optical phonons cause either a reduction of the electron density or an increase of the electron concentration in the channel region, depending on the phonon energy and coupling strength. Finally, we show that the critical length for carriers to get backscattered in the silicon nanowire is directly proportional to the phonon energy

Transport Spectroscopy of a Single Dopant in a Gated Silicon Nanowire

We report on spectroscopy of a single dopant atom in silicon by resonant tunneling between source and drain of a gated nanowire etched from silicon on insulator. The electronic states of this dopant isolated in the channel appear as resonances in the low temperature conductance at energies below the conduction band edge. We observe the two possible charge states successively occupied by spin-up and spin-down electrons under magnetic field. The first resonance is consistent with the binding energy of the neutral D0 state of an arsenic donor. The second resonance shows a reduced charging energy due to the electrostatic coupling of the charged D? state with electrodes. Excited states and Zeeman splitting under magnetic field present large energies potentially useful to build atomic scale devices.Kavli Institute of NanoscienceApplied Science