The Topological Relation Between Bulk Gap Nodes and Surface Bound States : Application to Iron-based Superconductors

In the past few years materials with protected gapless surface (edge) states have risen to the central stage of condensed matter physics. Almost all discussions centered around topological insulators and superconductors, which possess full quasiparticle gaps in the bulk. In this paper we argue systems with topological stable bulk nodes offer another class of materials with robust gapless surface states. Moreover the location of the bulk nodes determines the Miller index of the surfaces that show (or not show) such states. Measuring the spectroscopic signature of these zero modes allows a phase-sensitive determination of the nodal structures of unconventional superconductors when other phase-sensitive techniques are not applicable. We apply this idea to gapless iron based superconductors and show how to distinguish accidental from symmetry dictated nodes. We shall argue the same idea leads to a method for detecting a class of the elusive spin liquids.Comment: updated references, 6 pages, 4 figures, RevTex

Hardware accelerator for real-time holographic projector

With increasing popularity holographic method, 3D scene and augmented reality, needless to say, that 3D holography would be playing the most important role of real-time recording display. This paper demonstrates a setup that shows and records the scene in a real-time 3D appearance. We speed up the holographic processing by using a hardware accelerator to take advantage of its parallel specificities (architecture). The results clarify the system’s ability for viewing the holographic objects by applying four cameras running at the same time with a difference in partial of millisecond attributed to reason the clock of cameras and the VGA update.</p