Document Type : Research

Authors

1 Professor, Department of Physics, Payame Noor University, Tehran, Iran.

2 Associate Professor, Payame Noor University, Tehran, Iran.

3 Ph.D. Student, Department of Physics, Payame Noor University, Tehran, Iran.

Abstract

This paper investigates the structure of Josephson junctions, which, as one of the most fundamental elements in superconductivity, play a key role in the advancement of condensed matter physics, quantum field theory, and modern quantum technologies. The governing equation for the phase of such a system in the absence of dissipation and dispersion is the ordinary sine-Gordon equation, which describes fluxon propagation without considering the effects of dissipation and dispersion. However, in real physical system, the constituent materials of Josephson junctions always accompanied by dissipation and dispersion, which can significantly affect the dynamical behavior of fluxons. Here, by generalizing the sine-Gordon equation and including terms corresponding to dissipation and dispersion, and also considering the normalized bias current as a control parameter, the dynamics of fluxons in Josephson junctions have been studied. The result of this study show that the effects of dissipation and dispersion, especially in the presence of a normalized  bias current, play a  decisive role in the stability, propagation velocity of fluxons. The findings of this research confirm that considering dissipation and dispersion coefficients is essential and cannot be neglected in most cases.  According to the calculations and simulations performed, it is observed that the effect of loss and dispersion can be compensated with the help of bias current. Therfore, the studies presented in this paper can be considered an effective step towards more realistic simulation of fluxon dynamics in parctical superconducting system.

Keywords

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