15,471 research outputs found
Comments on N = 2 supersymmetric sigma models in projective superspace
For the most general off-shell N = 2 supersymmetric sigma model in projective
superspace, we elaborate on its formulation in terms of N = 1 chiral
superfields. A universal (model-independent) expression is obtained for the
holomorphic symplectic two-form, which determines the second supersymmetry
transformation. This two-form is associated with the two complex structures of
the hyperkahler target space, which are complimentary to the one used to
realize the target space as a Kahler manifold.Comment: 7 pages; V2: reference [18] correcte
A Hardy's Uncertainty Principle Lemma in Weak Commutation Relations of Heisenberg-Lie Algebra
In this article we consider linear operators satisfying a generalized
commutation relation of a type of the Heisenberg-Lie algebra. It is proven that
a generalized inequality of the Hardy's uncertainty principle lemma follows.
Its applications to time operators and abstract Dirac operators are also
investigated
Electro-Mechanical Simulation of Switching Characteristics for Nanoelectromechanical Memory
The static switching properties and readout characteristics of proposed high-speed and nonvolatile nanoelectromechanical (NEM) memory devices are investigated By conducting a three-dimensional finite element mechanical simulation combined with an electrostatic analysis, we analyze the electromechanical switching operation of a mechanically bistable NEM floating gate by applying gate voltage. We show that switching voltage can be reduced to less than 10V by reducing the zero-bias displacement of the floating gate and optimizing the cavity structure to improve mechanical symmetry. We also analyze the electrical readout property of the NEM memory devices by combining the electromechanical simulation with a drift-diffusion analysis We demonstrate that the mechanically bistable states of the floating gate can be detected via the changes in drain current with an ON/OFF current ratio of about 3 x 10 (C) 2009 The Japan Society of Applied Physic
Monolithic Ge:Ga Detector Development for SAFARI
We describe the current status and the prospect for the development of
monolithic Ge:Ga array detector for SAFARI. Our goal is to develop a 64x64
array for the 45 -- 110 um band, on the basis of existing technologies to make
3x20 monolithic arrays for the AKARI satellite. For the AKARI detector we have
achieved a responsivity of 10 A/W and a read-out noise limited NEP (noise
equivalent power) of 10^-17 W/rHz. We plan to develop the detector for SAFARI
with technical improvements; significantly reduced read-out noise with newly
developed cold read-out electronics, mitigated spectral fringes as well as
optical cross-talks with a multi-layer antireflection coat. Since most of the
elemental technologies to fabricate the detector are flight-proven, high
technical readiness levels (TRLs) should be achieved for fabricating the
detector with the above mentioned technical demonstrations. We demonstrate some
of these elemental technologies showing results of measurements for test
coatings and prototype arrays.Comment: To appear in Proc. Workshop "The Space Infrared Telescope for
Cosmology & Astrophysics: Revealing the Origins of Planets and Galaxies".
Eds. A.M. Heras, B. Swinyard, K. Isaak, and J.R. Goicoeche
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