A Superconductor Made by a Metal Heterostructure at the Atomic Limit Tuned at the "Shape Resonance": MgB2

We have studied the variation of Tc with charge density and lattice parameters in Mg1-xAlxB2 superconducting samples at low Al doping x<8%. We show that high Tc occurs where the chemical potential is tuned at a "superconducting shape resonance" near the energy Ec of the quantum critical point (QCP) for the dimensional transition from 2D to 3D electronic structure in a particular subband of the natural superlattice of metallic atomic boron layers. At the "shape resonance" the electrons pairs see a 2D Fermi surface at EF-w0 and a 3D Fermi surface at EF+wo, where wo is the energy cut off of the pairing interaction. The resonant amplification occurs in a narrow energy range where EF-Ec is in the range of 2wo.Comment: 16 page

President Lincoln\u27s Side-Profile Plaque

This is a round bronze plaque depicting a right-side relief head of Abraham Lincoln.https://scholarsjunction.msstate.edu/fvw-statuettes-and-figurines/1179/thumbnail.jp

Russell Horiuchi, Ellen, and Annette Horiuchi

Color photo of Horiuchi family at the Great Salt Lake. Ellen (the donor) is the child in the middle

Doll

In this view, the doll is seated in a small chair. She is wearing a green dress with white lace and black shoes

Fort Monroe, Virginia

Photograph of Eva Scot

Dining Hall No. 2.

Postcard of the Valmora Sanatorium with a view of the dining hall in Valmora, New Mexico

View from a Distance No.8.

Postcard of the Valmora Sanatorium with a view of the sanatorium from a distance in Valmora, New Mexico