31,623 research outputs found
Shot noise in frustrated single-electron arrays
We have carried out numerical simulations of shot noise in 2D arrays of
single-electron islands with random background charges. The results show that
in contrast with the 1D arrays, at low currents the current noise is strongly
colored, and its spectral density levels off at very low frequencies. The Fano
factor may be much larger than unity, due to the remnants of
single-electron/hole avalanches. However, even very small thermal fluctuations
reduce the Fano factor below 1 for almost any bias.Comment: 3 pages, 4 figure
Novel Approach to Super Yang-Mills Theory on Lattice - Exact fermionic symmetry and "Ichimatsu" pattern -
We present a lattice theory with an exact fermionic symmetry, which mixes the
link and the fermionic variables. The staggered fermionic variables may be
reconstructed into a Majorana fermion in the continuum limit. The gauge action
has a novel structure. Though it is the ordinary plaquette action, two
different couplings are assigned in the ``Ichimatsu pattern'' or the checkered
pattern. In the naive continuum limit, the fermionic symmetry survives as a
continuum (or an ) symmetry. The transformation of the fermion is
proportional to the field strength multiplied by the difference of the two
gauge couplings in this limit. This work is an extension of our recently
proposed cell model toward the realization of supersymmetric Yang-Mills theory
on lattice.Comment: 26 pages, 4 figure
Scar Intensity Statistics in the Position Representation
We obtain general predictions for the distribution of wave function
intensities in position space on the periodic orbits of chaotic ballistic
systems. The expressions depend on effective system size N, instability
exponent lambda of the periodic orbit, and proximity to a focal point of the
orbit. Limiting expressions are obtained that include the asymptotic
probability distribution of rare high-intensity events and a perturbative
formula valid in the limit of weak scarring. For finite system sizes, a single
scaling variable lambda N describes deviations from the semiclassical N ->
infinity limit.Comment: To appear in Phys. Rev. E, 10 pages, including 4 figure
The development of absorptive capacity-based innovation in a construction SME
Traditionally, construction has been a transaction-oriented industry. However, it is changing from the design-bid-build process into a business based on innovation capability and performance management, in which contracts are awarded on the basis of factors such as knowledge, intellectual capital and skills. This change presents a challenge to construction-sector SMEs with scarce resources, which must find ways to innovate based on those attributes to ensure their future competitiveness. This paper explores how dynamic capability, using an absorptive capacity framework in response to these challenges, has been developed in a construction-based SME. The paper also contributes to the literature on absorptive capacity and innovation by showing how the construct can be operationalized within an organization. The company studied formed a Knowledge Transfer Partnership using action research over a two-year period with a local university. The aim was to increase its absorptive capacity and hence its ability to meet the changing market challenges. The findings show that absorptive capacity can be operationalized into a change management approach for improving capability-based competitiveness. Moreover, it is important for absorptive capacity constructs and language to be contextualized within a given organizational setting (as in the case of the construction-based SME in the present study)
A Search For Solar Hadronic Axions Using Kr-83
We introduce a new experimental method for solar hadronic axions search. It
is suggested that these axions are created in the Sun during M1 transition
between the first thermally excited level at 9.4 keV and the ground state in
. Our method is based on axion detection via resonant absorption
process by the same nucleus in the laboratory. We use proportional gas counter
filled with krypton to detect signals for axions. With this setup, target and
detector are the same which increases the efficiency of the experiment. At
present, an upper limit on hadronic axion mass of 5.5 keV at the 95% confidence
level is obtained.Comment: 3 pages, contribution to ISRP9 Conference in Cape Town 2003. Version
accepted by Radiat. Phys. Che
Poynting Vector Flow in a Circular Circuit
A circuit is considered in the shape of a ring, with a battery of negligible
size and a wire of uniform resistance. A linear charge distribution along the
wire maintains an electrostatic field and a steady current, which produces a
constant magnetic field. Earlier studies of the Poynting vector and the rate of
flow of energy considered only idealized geometries in which the Poynting
vector was confined to the space within the circuit. But in more realistic
cases the Poynting vector is nonzero outside as well as inside the circuit. An
expression is obtained for the Poynting vector in terms of products of
integrals, which are evaluated numerically to show the energy flow. Limiting
expressions are obtained analytically. It is shown that the total power
generated by the battery equals the energy flowing into the wire per unit time.Comment: 19 pages, 8 figure
Generic Two-Qubit Photonic Gates Implemented by Number-Resolving Photodetection
We combine numerical optimization techniques [Uskov et al., Phys. Rev. A 79,
042326 (2009)] with symmetries of the Weyl chamber to obtain optimal
implementations of generic linear-optical KLM-type two-qubit entangling gates.
We find that while any two-qubit controlled-U gate, including CNOT and CS, can
be implemented using only two ancilla resources with success probability S >
0.05, a generic SU(4) operation requires three unentangled ancilla photons,
with success S > 0.0063. Specifically, we obtain a maximal success probability
close to 0.0072 for the B gate. We show that single-shot implementation of a
generic SU(4) gate offers more than an order of magnitude increase in the
success probability and two-fold reduction in overhead ancilla resources
compared to standard triple-CNOT and double-B gate decompositions.Comment: 5 pages, 3 figure
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