Sum rules for the energy levels of a hyperfine multiplet in a constant uniform magnetic field is presented. It is found that for any values of the electron angular moment and the nuclear spin there are certain linear combinations of energy levels which do not depend on the magnetic field and can be used to determine the unperturbated hfs separation in the presence of perturbing magnetic field. ...

The temperature dependence of coherent carrier transport in quantum cascade lasers (QCLs) is studied in this paper. It was found that coherent carrier transport in QCLs decreases as the temperature increases because the coherence between the injector and active region energy levels decays at a faster rate with increasing temperature. Calculations show that the coherence time decreases by at lea...

We present a comparative study on the quantum size effects in CdS and CdSe spherical dots, using first-principles derived semi-empirical pseudopotential method. Various properties including single-particle energy levels, characterization of individual electron wave functions, interband and intraband transitions, electron-hole Coulomb and exchange interactions, and excitonic band gap are investi...

Positronium (Ps) is a purely leptonic hydrogen-like atom formed from an electron and a positron. Since the interactions of electrons and positrons are thought to be almost entirely electromagnetic, precision measurements of the Ps energy levels should constitute a good test of QED theory. The ultimate precision is limited by the rapid annihilation of the various Ps states and the number of Ps a...

We present spatially resolved vibronic spectroscopy of individual pentacene molecules in a double-barrier tunneling junction. It is observed that even for this effective single-level system the energy dissipation associated with electron attachment varies spatially by more than a factor of 2. This is in contrast to the usual treatment of electron-vibron coupling in the Franck-Condon picture. Ou...

Recent electron beam driven plasma wakefield accelerator experiments carried out at SLAC indicate trapping of plasma electrons. More charge came out of than went into the plasma. Most of this extra charge had energies at or below the 10 MeV level. In addition, there were trapped electron streaks that extended from a few GeV to tens of GeV, and there were mono-energetic trapped electron bunches ...

Correlated ab initio electronic structure calculations are reported for the polymers lithium hydride chain [LiH]∞ and beryllium hydride [Be2H4]∞. First, employing a Wannier-function-based approach, the systems are studied at the Hartree-Fock level, by considering chains, simulating the infinite polymers. Subsequently, for the model system [LiH]∞, the correlation effects are computed by consider...