Late Triassic (Rhaetian) conodonts and ichthyoliths from Chile

The Late Triassic of the back arc Domeyko Basin, Chile is characterized by the onset of marine sedimentation that persisted throughout the rest of the Mesozoic. Carbonate bulk samples from the Punta del Viento Limestone Formation have yielded a numerically small, but apparently widespread, conodont fauna including Epigondolella mosheri, Epigondolella englandi and Neogondolella steinbergensis. These specimens indicate a Rhaetian (Epigondolella mosheri conodont Biozone roughly equivalent to the Paracochloceras amoenum ammonoid Biozone) age for this unit. Their recovery represents the first record of conodonts from Chile, and also indicates a considerable potential for use in correlating sequence stratigraphic events within the Mesozoic Marginal Sea in Colombia, Peru and Chile

Non-linear spin Seebeck effect due to spin-charge interaction in graphene

The abilities to inject and detect spin carriers are fundamental for research on transport and manipulation of spin information. Pure electronic spin currents have been recently studied in nanoscale electronic devices using a non-local lateral geometry, both in metallic systems and in semiconductors. To unlock the full potential of spintronics we must understand the interactions of spin with other degrees of freedom, going beyond the prototypical electrical spin injection and detection using magnetic contacts. Such interactions have been explored recently, for example, by using spin Hall or spin thermoelectric effects. Here we present the detection of non-local spin signals using non-magnetic detectors, via an as yet unexplored non-linear interaction between spin and charge. In analogy to the Seebeck effect, where a heat current generates a charge potential, we demonstrate that a spin current in a paramagnet leads to a charge potential, if the conductivity is energy dependent. We use graphene as a model system to study this effect, as recently proposed. The physical concept demonstrated here is generally valid, opening new possibilities for spintronics

The Extended Invariant Factor Algorithm with Application to the Forney Analysis of Convolutional Codes

In his celebrated paper on the algebraic structure of convolutional codes, Forney showed that by using the invariant-factor theorem, one can transform an arbitrary polynomial generator matrix for an (n, k) convolutional code C into a basic (and ultimately a minimal) generator matrix for C. He also showed how to find a polynomial inverse for a basic generator matrix for C, and a basic generator matrix for the dual code C^⊥. In this paper, we will discuss efficient ways to do all these things. Our main tool is the “entended invariant factor algorithm,” which we introduce here