15 research outputs found
Resonant tunnelling between the chiral Landau states of twisted graphene lattices
A class of multilayered functional materials has recently emerged in which the component atomic layers are held together by weak van der Waals forces that preserve the structural integrity and physical properties of each layer. An exemplar of such a structure is a transistor device in which relativistic Dirac Fermions can resonantly tunnel through a boron nitride barrier, a few atomic layers thick, sandwiched between two graphene electrodes. An applied magnetic field quantises graphene's gapless conduction and valence band states into discrete Landau levels, allowing us to resolve individual inter-Landau level transitions and thereby demonstrate that the energy, momentum and chiral properties of the electrons are conserved in the tunnelling process. We also demonstrate that the change in the semiclassical cyclotron trajectories, following an inter-layer tunnelling event, is analogous to the case of intra-layer Klein tunnelling
Sources of productivity spillovers: panel data evidence from China
This paper assesses sources of productivity spillovers in China\u27s electric and electronic manufacturing industry using a rich panel data-set of 25,360 firms observed over the period 2004-2007. This industry is characterized by its important reliance on technology. In particular, the paper focuses on the role of other firms\u27 productivity as well as productivity shifters in affecting own firm-level total factor productivity. In addition, this paper examines the possible difference between spillovers from foreign-owned units and from units which participate at global markets through exporting in comparison to domestically-owned and non-exporting units. We find evidence of stronger spillovers from exporting firms than from non-exporting firms. This is true for foreign-owned as well as domestic exporters. The strength of the spillover effects differ across subsectors
Health Aspects of the Pre-Departure Phase of Migration
In the second article in a six-part PLoS Medicine series on
Migration & Health, Brian Gushulak and Douglas MacPherson discuss the
pre-departure phase of migration and the specific health risks and policy needs
associated with this phase
Individual Preferences and Social Interactions Determine the Aggregation of Woodlice
n°e17389.info:eu-repo/semantics/publishe