Investigation of Josephson Contacts Pb0.6In0.4/KFe2As2 and KFe2As2/KFe2As2 and Order Parameter Symmetry Check

• Published in: Journal of experimental and theoretical physics Vol. 136; no. 2; pp. 155 - 162
• Main Authors: Golubkov, M. V., Stepanov, V. A., Sadakov, A. V., Usol’tsev, A. S., Morozov, I. V.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.02.2023; Springer Nature B.V
• Subjects: Classical and Quantum Gravitation; Critical temperature; Current voltage characteristics; Disorder; Electromagnetic radiation; Elementary Particles; Mathematical models; Order; Order parameters; Particle and Nuclear Physics; Phase Transition in Condensed System; Physics; Physics and Astronomy; Quantum Field Theory; Relativity Theory; Solid State Physics; Superconductors; Symmetry
• ISSN: 1063-7761; 1090-6509
• DOI: 10.1134/S1063776123020085

The characteristics of point Josephson contacts Pb 0.6 In 0.4 /KFe 2 As 2 and KFe 2 As 2 /KFe 2 As 2 have been studied. The temperature dependences of characteristic contact voltages V C ( T ) and the dependences of the first current step amplitudes in I – V characteristics on the power of 7.6-GHz electromagnetic radiation have been measured. It has been found that V C ( T ) curves for all contacts can be described in terms of the SIS*IS contact model (S, I, and S* stand for superconductor, insulator, and superconductor with a lower critical temperature, respectively) for superconductors with the s- symmetry of order parameter. It has been proved that the current step oscillation period as a function of microwave power can be exactly approximated with the resistive model of contact with I S = I C sin(φ). Obtained data are consistent with the normal s -symmetry of order parameter.