Electronic Transport in a Three-dimensional Network of 1-D Bismuth Quantum Wires

The resistance R of a high density network of 6 nm diameter Bi wires in porous Vycor glass is studied in order to observe its expected semiconductor behavior. R increases from 300 K down to 0.3 K. Below 4 K, where R varies approximately as ln(1/T), the order-of-magnitude of the resistance rise, as well as the behavior of the magnetoresistance are consistent with localization and electron-electron interaction theories of a one-dimensional disordered conductor in the presence of strong spin-orbit scattering. We show that this behaviour and the surface-enhanced carrier density may mask the proposed semimetal-to-semiconductor transition for quantum Bi wires.Comment: 19 pages total, 4 figures; accepted for publication in Phys. Rev.

Using derivative logic to speculate on the future of the social investment market

This article pries open the black box of the social impact bond (SIB), the novel financial instrument at the heart of social investment. We discover that concrete information is currently limited and our method is thus more speculative. We address the obfuscation of the nomenclature of the instrument and explore the mechanics of SIBs to suggest that they are not simple bonds but rather also bear properties akin to those associated with derivative contracts. We speculate on possible developments of the market in these bonds by considering the history of some previous financial innovations, namely, collateralized debt obligations (CDOs) underpinned by microfinance loans and the short-lived policy analysis market. Our discussion leads us to reevaluate Goodhart’s law and the ways in which it operates in relation to SIBs. We conclude by suggesting that SIBs' inherent indifference to the underlying state of the world renders them ultimately unlikely to delivery improvements in public services

The autonomous city: towards a critical geography of occupation

This paper explores the recent resurgence of occupation-based practices across the globe, from the seizure of public space to the assembling of improvised protest camps. It re-examines the relationship between the figure of occupation and the affirmation of an alternative ‘right to the city’. The paper develops a critical understanding of occupation as a political process that prefigures and materializes the social order which it seeks to enact. The paper highlights the constituent role of occupation as an autonomous form of urban dwelling, as a radical politics of infrastructure and as a set of relations that produce common spaces for political action