Limitation of the frequency dispersion of electromagnetic radiation produced by fluxons.

The work found the shape of spectral lines of electromagnetic radiation produced by a relativistic quantum of magnetic flux moving in a Josephson transmission line under the action of a purely fluctuating external current and dissipation. It is shown that even in the case of a Gaussian noise current, the shape of the spectral lines of electromagnetic radiation has an essentially non-Gaussian form. The limited dispersion of the frequency of electromagnetic radiation (which is determined by the pinching of the spectral lines of radiation) is proved, due to the relativistic properties of the quantum magnetic flux. This is another unique aspect of the relativistic quantum magnetic flux - as a carrier of electromagnetic radiation in the Josephson transmission line.

FLUX CLONING ANOMALITIES IN JOSEPHSON NANO-JUNCTIONS

The propagation of single flux quanta in T -shaped Josephson junctions gives rise to the flux cloning phenomenon. We have studied numerically the dynamics of flux cloning in cases of extended Josephson junctions. The changing thicknesses of T -junctions lead to new and interesting effects in terms of their dynamics. We have found out that when an additional Josephson transmission line is larger than the main Josephson transmission line, numerical simulations do not show the cloning phenomenon and soliton is reflected when it approaches the T junction. This strange result may be happened because the soliton losses more energy in the sharp edge. Although the vortex is moving very highly and it has huge energy but it still does not give birth to a new vortex. We have investigated conditions at which flux cloning occurs when both widths, W and W0, are changing.

MODIFIED JOSEPHSON EQUATION AND MEASUREMENT DYNAMICS FOR THE JOSEPHSON TRANSMISSION LINE DETECTOR

By introducing the entangled state representation and following Feynman's assumption that "electron pairs are bosons … A bound pair acts as a Bose particle", we construct a Hamiltonian operator for the Josephson transmission line (JTL) detector, then we use the Heisenberg equation of motion to derive the modified Josephson equation. Based on the modified Josephson equation, the measurement dynamics of JTL detector is investigated, which will be helpful for us to analyze the quantum measurement of JTL detector.