Time domain simulation of shapiro steps in Josephson junctions

Journal Article · Fri Mar 01 04:00:00 EST 1985 · IEEE Trans. Magn.; (United States)

DOI:https://doi.org/10.1109/TMAG.1985.1063753· OSTI ID:6081591

Imai, S; Mikoshiba, N; Morita, S; Shinagawa, M; Takeuti, Y

Using the time domain formulation of the theory of the tunnel junction. We investigated Shapiro steps by digital simulation, under the condition of a constant current source given by I /SUB dc/ +I /SUB rf/ sin..omega..t. The integral kernels for the Josephson and the quasiparticle current were computed assuming a nonzero pair breaking parameter delta=0.1, and T=OK. We obtained I /SUB rf/ dependence of the zeroth and first Shapiro steps, I/sub 0/ and I/sub 1/, and the frequency dependence of I/sub 1/ /SUP MAX/ , the maximum of the first Shapiro step as a function of I /SUB rf/ , for a few values of the junction capacitance. We found the following results. (1) I/sub 1/ /SUP MAX/ /I /SUB c/ (I /SUB c/ : the critical current), showed the Riedel peak at ..omega../..omega.. /SUB g/ approx. =1, where ..omega.. /SUB g/ is the gap frequency 4 ..delta../n. (2) For ..omega../..omega.. /SUB g/ >1, I/sub 1/ /SUP MAX/ /I /SUB c/ agrees well with that for the constant voltage bias. (3) As the frequency becomes smaller below ..omega.. /SUB g/ , I/sub 1/ /SUP MAX/ /I /SUB c/ is severely depressed compared to that for the constant voltage bias.

• Research Organization: Research Institute of Electrical Communication Tohoku University
• OSTI ID: 6081591
• Journal Information: IEEE Trans. Magn.; (United States), Journal Name: IEEE Trans. Magn.; (United States) Vol. MAG-21:2; ISSN IEMGA
• Country of Publication: United States
• Language: English

Related Subjects

420201* -- Engineering-- Cryogenic Equipment & Devices
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CAPACITANCE
COMPUTERIZED SIMULATION
CRITICAL CURRENT
CURRENTS
ELECTRIC CURRENTS
ELECTRICAL PROPERTIES
ENERGY GAP
FREQUENCY DEPENDENCE
JOSEPHSON JUNCTIONS
JUNCTIONS
PHYSICAL PROPERTIES
SIMULATION
SUPERCONDUCTING JUNCTIONS
TIME DEPENDENCE
TIMING PROPERTIES