36,928 research outputs found
Time-dependent coupled oscillator model for charged particle motion in the presence of a time varyingmagnetic field
The dynamics of time-dependent coupled oscillator model for the charged
particle motion subjected to a time-dependent external magnetic field is
investigated. We used canonical transformation approach for the classical
treatment of the system, whereas unitary transformation approach is used when
managing the system in the framework of quantum mechanics. For both approaches,
the original system is transformed to a much more simple system that is the sum
of two independent harmonic oscillators which have time-dependent frequencies.
We therefore easily identified the wave functions in the transformed system
with the help of invariant operator of the system. The full wave functions in
the original system is derived from the inverse unitary transformation of the
wave functions associated to the transformed system.Comment: 16 page
Spin-transfer torque in magnetic multilayer nanopillars
We consider a quasi one-dimensional configuration consisting of two small
pieces of ferromagnetic material separated by a metallic one and contacted by
two metallic leads. A spin-polarized current is injected from one lead. Our
goal is to investigate the correlation induced between the magnetizations of
the two ferromagnets by spin-transfer torque. This torque results from the
interaction between the magnetizations and the spin polarization of the
current. We discuss the dynamics of a single ferromagnet, the extension to the
case of two ferromagnets, and give some estimates for the parameters based on
experiments.Comment: To appear in the Journal of Physics: Conference Series (Proceedings
of the International Conference on Nanoscience and Technology, Basel, 2006
Putative spin liquid in the triangle-based iridate BaIrTiO
We report on thermodynamic, magnetization, and muon spin relaxation
measurements of the strong spin-orbit coupled iridate BaIrTiO,
which constitutes a new frustration motif made up a mixture of edge- and
corner-sharing triangles. In spite of strong antiferromagnetic exchange
interaction of the order of 100~K, we find no hint for long-range magnetic
order down to 23 mK. The magnetic specific heat data unveil the -linear and
-squared dependences at low temperatures below 1~K. At the respective
temperatures, the zero-field muon spin relaxation features a persistent spin
dynamics, indicative of unconventional low-energy excitations. A comparison to
the isostructural compound BaRuTiO suggests that a concerted
interplay of compass-like magnetic interactions and frustrated geometry
promotes a dynamically fluctuating state in a triangle-based iridate.Comment: Physical Review B accepte
Recommended from our members
XAI-Explainable artificial intelligence
Explainability is essential for users to effectively understand, trust, and manage powerful artificial intelligence applications
Impacts of different dietary lipid sources on growth performance, fatty acid composition and antioxidant enzyme activity of juvenile black sea bream, Acanthopagrus schlegeli
The aim of the present study was to evaluate the impacts of diets supplemented with different lipid sources on growth performance, body composition, fatty acid profile, and hepatic antioxidant enzyme activity of juvenile black sea bream, Acanthopagrus schlegeli (initial mean weight, 1.1±0.02g). Four isonitrogenous and isolipidic diets were formulated with either fish oil (FO), soybean oil (SO), linseed oil (LO) or a mixture of SO and LO (SO+LO). The results showed that survival, weight gain, feed efficiency and protein efficiency ratios of black sea bream were not affected by dietary lipid sources (p>0.05). Liver and muscle of fish fed the SO diet had high concentration of linoleic acid, while those of fish fed the LO diet were high in linolenic acid. Liver and muscle of fish fed the FO diet had significantly (p<0.05) higher levels of eicosapentaenoic acid and docosahexaenoic acid, compared to fishes fed the SO and LO diets. Superoxide dismutase and glutathione peroxidase enzymes activities in liver of black sea bream were not influenced by dietary lipid sources. Our findings suggest that SO and/or LO can be used as a substitute for FO in black sea bream diets without adverse effects on growth performance and antioxidant enzyme activity, when the essential fatty acid requirements are present in diets for black sea bream
Nonlinear couplings and tree amplitudes in gauge theories
Following a remark advanced by Feynman,we study the connection between the
form of the nonlinear vertices involving gauge particles and the Abelian gauge
invariance of physical tree amplitudes. We show that this requirement, together
with some natural assumptions, fixes uniquely the structure of the Yang-Mills
theory. However, the constraints imposed by the above property are not
sufficient to single out the gauge theory of gravitation.Comment: 12 pages. Requires macros RevTeX, prepictex, pictex, postpictex. TeX
source is 69373 byte
Testing the SUSY-QCD Yukawa coupling in a combined LHC/ILC analysis
In order to establish supersymmetry (SUSY) at future colliders, the identity
of gauge couplings and the corresponding Yukawa couplings between gauginos,
sfermions and fermions needs to be verified. Here a first phenomenological
study for determining the Yukawa coupling of the SUSY-QCD sector is presented,
using a method which combines information from LHC and ILC.Comment: 5pp, slightly expanded version of contributions to the Proc. of the
Linear Collider Workshop (LCWS 06), Bangalore, India, 9-13 March 2006, and
the Proc. of the 14th International Conference on Supersymmetry and the
Unification of Fundamental Interactions (SUSY 06), Irvine, California, USA,
12-17 June 200
- …