3,980 research outputs found
Steady state current transfer and scattering theory
The correspondence between the steady state theory of current transfer and
scattering theory in a system of coupled tight-binding models of 1-dimensional
wires is explored. For weak interwire coupling both calculations give nearly
identical results, except at singular points associated with band edges. The
effect of decoherence in each of these models is studied using a generalization
of the Liouville-von Neuman equation suitable for steady-state situations. An
example of a single impurity model is studied in details, leading to a lattice
model of scattering off target that affects both potential scattering and
decoherence. For an impurity level lying inside the energy band, the
transmission coefficient diminishes with increasing dephasing rate, while the
opposite holds for impurity energy outside the band. The efficiency of current
transfer in the coupled wire system decreases with increasing dephasing.Comment: 22 pages, 13 figure
Steady state theory of current transfer
Current transfer is defined as a charge transfer process where the
transferred charge carries information about its original motion. We have
recently suggested that such transfer causes the asymmetry observed in electron
transfer induced by circularly polarized light through helical wires. This
paper presents the steady state theory of current transfer within a tight
binding model of coupled wires systems. The efficiency of current transfer is
quantified in terms of the calculated asymmetry in the system response to a
steady current imposed on one of the wires, with respect to the imposed current
direction.Comment: 25 pages, 14 figure
Anisotropic thermal magnetoresistance for an active control of radiative heat transfer
We predict a huge anisotropic thermal magnetoresistance (ATMR) in the
near-field radiative heat transfer between magneto-optical particles when the
direction of an external magnetic field is changed with respect to the heat
current direction. We illustrate this effect with the case of two InSb
spherical particles where we find that the ATMR amplitude can reach values of
up to 800% for a magnetic field of 5 T, which is many orders of magnitude
larger than its spintronic analogue in electronic devices. This thermomagnetic
effect could find broad applications in the fields of ultrafast thermal
management as well as magnetic and thermal remote sensing.Comment: 6 pages, 4 figure
In-Network Retransmissions in Named Data Networking
The strategy layer is an important architectural component in both Content-Centric Networking (CCN) and Named Data Networking (NDN). This component introduces a new forwarding model that allows an application to configure its namespace with a forwarding strategy. A core mechanism in every forwarding strategy is the decision of whether to retransmit an unsatisfied Interest or to wait for an application retransmission. While some applications request control of all retransmissions, others rely on the assumption that the strategy will retransmit an Interest when it is not satisfied. Although an application can select the forwarding strategy used in the local host, it cannot guarantee the selection of the same strategy in other nodes in the network, especially in shared resource environments. In some scenarios, a developer must bind the implementation of the application to the details of the deployed forwarding strategy to guarantee the correctness of his application. In this paper we discuss the core mechanisms of a forwarding strategy in NDN, and we explore the importance and impact of in-network retransmissions on the application\u27s performance and correctness. We propose and implement a simple forwarding strategy abstraction that allows the application to decide whether a network retransmission is required, and differentiate application retransmissions from network retransmissions. We show that in some scenarios, such as multiple producers application or multipath consumer-producer service, the proposed abstraction can significantly reduce the percentage of unsatisfied Interests
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