Coincidence of features of emitted THz electromagnetic wave power form a single Josephson junction and different current components

• Published in: Physica. C, Superconductivity Superconductivity, 2017-12, Vol.543, p.62-64
• Main Author: Hamdipour, Mohammad
• Format: Article
• Language: English
• Subjects: Alternating current; Charge density; Current voltage characteristics; Electric fields; Electromagnetics; Josephson junction; Studies; Superconductivity; Superconductors; Terahertz emission; Throwing; Wave power
• ISSN: 0921-4534; 1873-2143
• DOI: 10.1016/j.physc.2017.10.006

•Emitted THz wave power form a Josephson junction, (JJ), is found numerically.•Correlation of charge in superconducting layers of a JJ are derived.•Coincidence of features of average supercurrent and emitted THz power from a JJ.•THz emission from a JJ is related to motion of plasma wave in lateral direction of JJ. By applying a voltage to a Josephson junction, the charge in superconducting layers (S-layers) will oscillate. Wavelength of the charge oscillations in S-layers is related to external current in junction, by increasing the external current, the wavelength will decrease which cause in some currents the wavelength be incommensurate with width of junction, so the CVC shows Fiske like steps. External current throwing along junction has some components, resistive, capacitive and superconducting current, beside these currents there is a current in lateral direction of junction, (x direction). On the other hand, the emitted electromagnetic wave power in THz region is related to AC component of electric field in junction, which itself is related to charge density in S-layers, which is related to currents in the system. So we expect that features of variation of current components reflect the features of emitted THz power form junction. Here we study in detail the superconductive current in a long Josephson junction (JJ), the current voltage characteristics (CVC) of junction and emitted THz power from the system. Then we compare the results. Comparing the results we see that there is a good qualitative coincidence in features of emitted THz power and supercurrent in junction.