Quantum Spin Holography with Surface State Electrons

In a recent paper Moon and coworkers [C.R. Moon et al., Nature Nanotechnology 4, 167 (2009)] have shown that the single-atom limit for information storage density can be overcome by using the coherence of electrons in a two-dimensional electron gas to produce quantum holograms comprised of individually manipulated molecules projecting an electronic pattern onto a portion of a surface. We propose to further extend the concept by introducing quantum spin holography - a version of quantum holographic encoding allowing to store the information in two spin channels independently.Comment: 5 pages, 3 figure

Relativistic peculiarities at stepped surfaces: surprising energetics and unexpected diffusion patterns

We revive intriguing, yet still unexplained, experimental results of Ehrlich and co-workers [ Phys. Rev. Lett. 77 1334 (1996); Phys. Rev. Lett. 67 2509 (1991)] who have observed, that 5d adatoms distributed on (111) surface islands of 5d metals favor the adsorption at the cluster's edge rather than at the cluster's interior, which lies in contrast with the behavior of 4d and 3d elements. Our state of the art ab initio calculations demonstrate that such behavior is a direct consequence of the relativity of 5d metals.Comment: 5 pages, 5 figure

Confined bulk states as a long-range sensor for impurities and a transfer channel for quantum information

We show that confinement of bulk electrons can be observed at low-dimensional surface structures and can serve as a long-range sensor for the magnetism and electronic properties of single impurities or as a quantum information transfer channel with large coherence lengths. Our ab initio calculations reveal oscillations of electron density in magnetic chains on metallic surfaces and help to unambiguously identify the electrons involved as bulk electrons. We furthermore discuss the possibility of utilizing bulk state confinement to transfer quantum information, encoded in an atom's species or spin, across distances of several nanometers with high efficiency.Comment: 5 pages, 2 figure

Surface Geometry of 5D Black Holes and Black Rings

We discuss geometrical properties of the horizon surface of five-dimensional rotating black holes and black rings. Geometrical invariants characterizing these 3D geometries are calculated. We obtain a global embedding of the 5D rotating black horizon surface into a flat space. We also describe the Kaluza-Klein reduction of the black ring solution (along the direction of its rotation) which relates this solution to the 4D metric of a static black hole distorted by the presence of external scalar (dilaton) and vector (`electromagnetic') field. The properties of the reduced black hole horizon and its embedding in \E^3 are briefly discussed.Comment: 10 pages, 9 figures, Revtex