Fast and accurate single-island charge pump: implementation of a cooper pair pump

We introduce a Cooper pair "sluice" for the implementation of a frequency-locked current source. The device consists of two mesoscopic SQUIDs and of a single superconducting island with a gate. We demonstrate theoretically that it is possible to obtain a current as high as 0.1 nA at better than ppm accuracy via periodically modulating both the gate charge and the effective Josephson coupling. We find that the device is tolerant against background charge noise and operates well even in a dissipative environment. The effect of the imperfect suppression of the Josephson coupling and the finite operating frequency are also investigated.     

The transformation of aromatic molecules into the subspace of their double bonds

A model of new submolecules is presented. As an application some absorptions of aromatic radicals are interpreted in UV and visible spectra. Extension of the model to biological systems is prejudged.     

Efficient Behavioural Modelling of Small Timing Errors in A/D and D/A Converters

In this paper, methods for analyzing the effects of small timing errors in D/A and time-interleaved A/D converters are studied. It is shown that timing skew and slew rate in D/A converters cause broadband spurious components, but the output spectrum can in most cases be calculated simply by averaging the errors over one sample period and using FFT at the original sample rate. Also the frequency-domain effects of mismatch in time-interleaved A/D converters can be constructed by calculating the mixing transfer functions caused by the time-varying gain and timing.     

On Vekua Systems and Their Connections to Hyperbolic Function Theory in the Plane

In this paper we study the solutions of the equation $$\Delta w- \frac{\alpha}{y}\partial_{y}w = 0,$$ where w is a complex valued function. This equation is related to the generalized axially symmetric potential theory which has been studied notably by Weinstein, see [12]. We have researched this equation earlier in higher dimensions in connection with the hyperbolic function theory. In this paper will see how this equation is related to the generalized analytic functions in the hyperbolic upper half-plane. We also study harmonic differential forms in the hyperbolic plane and using these we obtain special type of solutions for the preceding equation.     

A Lesson on Unpredictable Future

This paper presents the main conclusions that can be drawn by the discussions on future communication systems addressed in details in the papers published in this issue of the journal and the lessons on unpredictable future of wireless communications.     

On $$$$-Hypermonogenic Functions and Their Mean Value Properties

We study a hyperbolic version of holomorphic functions to higher dimensions. In this frame work, a generalization of holomorphic functions are called \(k\)-hypermonogenic functions. These functions are depending on several real variables and their values are in a Clifford algebra. They are defined in terms of hyperbolic Dirac operators. They are connected to harmonic functions with respect to the Riemannian metric \(ds^{2}_k=x_{n}^{2k/\left( 1-n\right) }\left( dx_{0}^{2}+\cdots +dx_{n}^{2}\right) \) in the same way as the usual harmonic function to holomorphic functions. We present the mean value property for \(k\)-hypermonogenic functions and related results. Earlier the mean value properties has been proved for hypermonogenic functions. The key tools are the invariance properties of the hyperbolic metric.