Theoretical studies on the band structures of superconducting solid compounds: Nb₃X (X=Si, Ge, Sn, Pb)

Abstract

The band structures of several analogous superconducting A‐15 type solid compounds, Nb3X (X=Si, Ge, Sn, Pb), have been calculated by use of the tight‐binding method within the Extended Hückel approximation (EHT). By analysis of their energy bands, densities of states and crystal orbital overlap populations, the dependence of the superconducting transition temperatures (Tc) on the electronic structures and bondings is qualitatively elucidated.

Bound entanglement and teleportation for arbitrary bipartite systems

“…More efforts were done to analyze the entanglement of quantum states. [7][8][9][10][11][12] States which are entangled but not distillable are called bound entanglement. Bound entanglement has played very important roles in quantum information, especially in quantum teleportation.…”