The effect of laser fields on electron transport through a molecular wire weakly coupled to two leads is investigated. The molecular wire acts as a coherent quantum ratchet if the molecule is composed of periodically arranged, asymmetric chemical groups. This setup presents a quantum rectifier with a finite dc response in the absence of a static bias. The nonlinear current is evaluated in close...

We have modeled and simulate asymmetric microstrip folded dipole antenna on substrate materials and study the antenna performances. The conventional wire dipole antenna configurations are converted into corresponding microstrip version. The complementary nature of parallel coplanar strip line and waveguide models have been used to model the dipole antenna. The transmission line parameters namel...

Abstract Tailored forming is used to produce hybrid components in which the materials are locally adapted different types of physical, chemical and tribological requirements. In this paper, a Forming process chain for production shaft with bearing seat investigated. The consists manufacturing steps laser hot-wire cladding, cross-wedge rolling, turning deep rolling. A cylindrical bar made mild s...

The concept of ratchets, driven asymmetric periodic structures giving rise to directed particle flow, has recently been generalized to a quantum ratchet mechanism for spin currents mediated through spin-orbit interaction. Here we consider such systems in the coherent mesoscopic regime and generalize the proposal of a minimal spin ratchet model based on a non-interacting clean quantum wire with ...

We consider the problem of a sphere rolling on a curved surface and solve it by mapping it to the precession of a spin 1/2 in a magnetic field of variable magnitude and direction. The mapping can be of pedagogical use in discussing both rolling and spin precession. As an interesting example we show that the Landau-Zener problem corresponds to the rolling of a sphere on a Cornu spiral, and deriv...

We study the motion of C₆₀ fullerene molecules and short-length carbon nanotubes on graphene nanoribbons. We reveal that the character of the motion of C₆₀ depends on temperature: for T < 150 K the main type of motion is sliding along the surface, but for higher temperatures the sliding is replaced by rocking and rolling. Modeling of the buckyball with an included metal ion demonstrates that th...

Objects with bilateral symmetry, such as faces, animal shapes, and many man-made objects, play an important role in everyday vision. Because they occur frequently, it is reasonable to conjecture that the brain may be specialized for symmetric objects. We investigated whether the human visual system processes three-dimensional (3D) symmetric objects more efficiently than asymmetric ones. Human s...