Electron Tunneling into Intermediate-Valence Materials

Racah materials: role of atomic multiplets in intermediate valence systems

We address the long-standing mystery of the nonmagnetic insulating state of the intermediate valence compound SmB6. Within a combination of the local density approximation (LDA) and an exact diagonalization (ED) of an effective discrete Anderson impurity model, the intermediate valence ground state with the f-shell occupation 〈n4f〉 = 5.6 is found for the Sm atom in SmB6. This ground state is a ...

First-principles theory of intermediate-valence f-electron systems.

We propose a first-principles based method for calculating the electronic structure and total energy of solids in an intermediate-valence configuration. The method takes into account correlation effects (d-f Coulomb interaction) and many-body renormalization of the effective hybridization parameter of the f system. As an example, the formation of a pressure-induced intermediate-valence state in...

Anisotropic intermediate valence in Yb2Rh3Ga9

We report measurements of the inelastic neutron scattering spectrum for the anisotropic intermediate valence system Yb2Rh3Ga9. Calculations for the Anderson impurity model with crystal field terms within an approach based on the non-crossing approximation have been performed for the inelastic neutron scattering spectrum as well as other thermodynamic quantities. These results corroborate the im...

Quantum theory of electron tunneling into intersubband cavity polariton states

Modeling CMOS Tunneling Currents Through Ultrathin Gate Oxide Due to Conduction- and Valence-Band Electron and Hole Tunneling

A semi-empirical model is proposed to quantify the tunneling currents through ultrathin gate oxides (1–3.6 nm). As a multiplier to a simple analytical model [1], [2], a correction function is introduced to achieve universal applicability to all different combinations of bias polarities (inversion and accumulation), gate materials (N, P, Si, SiGe) and tunneling processes. Each coefficient of the...