in order to study some theories about nonsuperconductivity of prba2cu3o7, based on the density functional theory and with apw+lo/lapw method some calculations for prba2cu3o7 (pr123) and yba2cu3o7 (y123) were performed. the lsda+u approximation was used for pr(4f) orbitals and the effect of changing upr on the band structure, pr(4f)-dos, distribution of electrons on the planes and chains, and pr...

An accurate width is determined for the valence band of diamond by imaging photoelectron momentum distributions for a variety of initialand final-state energies. The experimental result of 23.060.2 eV agrees well with first-principles quasiparticle calculations ~23.0 and 22.88 eV! and significantly exceeds the localdensity-functional width, 21.560.2 eV. This difference quantifies effects of cre...

Stoichiometric FeRh undergoes a temperature-induced antiferromagnetic (AFM) to ferromagnetic (FM) transition at ~350 K. In this Letter, changes in the electronic structure accompanying this transition are investigated in epitaxial FeRh thin films via bulk-sensitive valence-band and core-level hard x-ray photoelectron spectroscopy with a photon energy of 5.95 keV. Clear differences between the A...

The electronic structure of AlN in wurtzite and zinc-blende phases is studied experimentally and theoretically. By using x-ray emission spectroscopy , the Al 3p , Al 3s and N 2p spectral densities are obtained. The corresponding local and partial theoretical densities of states (DOS) , as well as the total DOS and the band structure , are calculated by using the full potential linearized augmen...

The conductivity effective masses of electrons and holes in Si are calculated for carrier temperatures from 1 to 3000 K. The temperature dependence of the electron mass is calculated by use of a phenomenological model of conduction-band nonparabolicity that has been fitted to experimental measurements of the dependence of the electron conductivity effective mass on carrier concentration. The ho...

After two decades since the discovery of ferromagnetism in manganese-doped gallium arsenide, its origin is still debated, and many doubts are related to the electronic structure. Here we report an experimental and theoretical study of the valence electron spectrum of manganese-doped gallium arsenide. The experimental data are obtained through the differences between off- and on-resonance photo ...

It is shown that absorption of circularly polarized infrared radiation achieved by inter-subband and intra-subband (Drude-like) transitions results in a monopolar spin orientation of free carriers. The monopolar spin polarization in zinc-blende-based quantum wells (QWs) is demonstrated by the observation of the spin-galvanic and circular photogalvanic effects. It is shown that monopolar spin or...

It is shown that absorption of circularly polarized infrared radiation due to intraband (Drude-like) transitions in n-type bulk semiconductors and due to intra-subband or inter-subband transitions in quantum well (QW) structures results in a monopolar spin orientation of free electrons. Spin polarization in zinc-blende-structure based QWs is demonstrated by the observation of the spin-galvanic ...

The band offsets of non-polar A-plane GaN/AlN and AlN/GaN heterojunctions are measured by X-ray photoemission spectroscopy. A large forward-backward asymmetry is observed in the non-polar GaN/AlN and AlN/GaN heterojunctions. The valence-band offsets in the non-polar A-plane GaN/AlN and AlN/GaN heterojunctions are determined to be 1.33 ± 0.16 and 0.73 ± 0.16 eV, respectively. The large valence-b...

The study of the valence band ~VB! of diamond-type semiconductors goes back at least as far back as a paper by Shockley. Detailed study commenced in the classic paper by Dresselhaus, Kip, and Kittel in which the A , B , C parameters were introduced in a three-band k•p model to describe the structure of the VB; the parameters were determined from measurements of the effective mass as a function ...