ac Josephson effect for asymmetric superconducting junctions

Journal Article · Sat Nov 01 04:00:00 EST 1997 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.56.11232· OSTI ID:553992

Hurd, M; Datta, S; Bagwell, P F ^[1]

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1. Purdue University, School of Electrical and Computer Engineering, West Lafayette, Indiana 47907 (United States)

We calculate the ac and dc current-voltage (I-V) relation when a tunnel barrier is placed in the normal region of a superconductor{endash}normal-metal{endash}superconductor (S{sub 1}NS{sub 2}) junction, where the two superconducting contacts have different gaps ({Delta}{sub 2}{ge}{Delta}{sub 1}{ge}0). The voltages at which subharmonic gap structure (SGS) appears in the zero-temperature I-V are the same as previously found for the SGS in ballistic S{sub 1}NS{sub 2} junctions at a finite temperature. Some of the SGS{close_quote}s are strong enough to produce negative differential resistance. We determine the variation of the ac Josephson current with bias, junction transmissivity, gap ratio {Delta}{sub 1}/{Delta}{sub 2}, and junction length L. The ac Josephson current through a ballistic SNS junction can also be used to measure the superconducting phase difference {phi}. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 553992
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 17 Vol. 56; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ENERGY GAP
JOSEPHSON EFFECT
SUPERCONDUCTING JUNCTIONS