14,807 research outputs found
Processing techniques development, volume 3. Part 2: Data preprocessing and information extraction techniques
There are no author-identified significant results in this report
High efficiency deterministic Josephson Vortex Ratchet
We investigate experimentally a Josephson vortex ratchet -- a fluxon in an
asymmetric periodic potential driven by a deterministic force with zero time
average. The highly asymmetric periodic potential is created in an underdamped
annular long Josephson junction by means of a current injector providing
efficiency of the device up to 91%. We measured the ratchet effect for driving
forces with different spectral content. For monochromatic high-frequency drive
the rectified voltage becomes quantized. At high driving frequencies we also
observe chaos, sub-harmonic dynamics and voltage reversal due to the inertial
mass of a fluxon.Comment: accepted by PRL. To see status click on
http://134.2.74.170:88/cnt/cond-mat_0506754.htm
Variant supercurrent multiplets
In N = 1 rigid supersymmetric theories, there exist three standard
realizations of the supercurrent multiplet corresponding to the (i) old
minimal, (ii) new minimal and (iii) non-minimal off-shell formulations for N =
1 supergravity. Recently, Komargodski and Seiberg in arXiv:1002.2228 put
forward a new supercurrent and proved its consistency, although in the past it
was believed not to exist. In this paper, three new variant supercurrent
multiplets are proposed. Implications for supergravity-matter systems are
discussed.Comment: 11 pages; V2: minor changes in sect. 3; V3: published version; V4:
typos in eq. (2.3) corrected; V5: comments and references adde
Considerations on Super Poincare Algebras and their Extensions to Simple Superalgebras
We consider simple superalgebras which are a supersymmetric extension of
\fspin(s,t) in the cases where the number of odd generators does not exceed
64. All of them contain a super Poincar\'e algebra as a contraction and another
as a subalgebra. Because of the contraction property, some of these algebras
can be interpreted as de Sitter or anti de Sitter superalgebras. However, the
number of odd generators present in the contraction is not always minimal due
to the different splitting properties of the spinor representations under a
subalgebra. We consider the general case, with arbitrary dimension and
signature, and examine in detail particular examples with physical implications
in dimensions and .Comment: 16 pages, AMS-LaTeX. Version to appear in the Reviews in Mathematical
Physic
Snyder noncommutative space-time from two-time physics
We show that the two-time physics model leads to a mechanical system with
Dirac brackets consistent with the Snyder noncommutative space. An Euclidean
version of this space is also obtained and it is shown that both spaces have a
dual system describing a particle in a curved space-time.Comment: 5 pages, RevTeX4. References adde
Superconformal spaces and implications for superstrings
We clarify some properties of projective superspace by using a manifestly
superconformal notation. In particular, we analyze the N=2 scalar multiplet in
detail, including its action, and the propagator and its super-Schwinger
parameters. The internal symmetry is taken to be noncompact (after Wick
rotation), allowing boundary conditions that preserve it off shell.
Generalization to N=4 suggests the coset superspace PSU(2,2|4)/OSp(4|4) for the
AdS/CFT superstring.Comment: 19 pages, no figures; v2: fixed sign, added note & reference; v3:
added note & references, version to appear in Physical Review
Terahertz local oscillator sources: performance and capabilities
Frequency multiplier circuits based on planar GaAs Schottky diodes have advanced significantly in the last decade. Useful power in the >1 THz range has now been demonstrated from a complete solid-state chain. This paper will review some of the technologies that have led to this achievement along with a brief look at future challenges
Method for carbon dioxide splitting
A method for splitting carbon dioxide via a two-step metal oxide thermochemical cycle by heating a metal oxide compound selected from an iron oxide material of the general formula AxFe3-xO4, where 0≦x≦1 and A is a metal selected from Mg, Cu, Zn, Ni, Co, and Mn, or a ceria oxide compound of the general formula MaCebOc, where
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