Control of Andreev-level occupation in a Josephson junction by a normal-metal probe

Journal Article · Thu May 01 04:00:00 EDT 1997 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.55.12678· OSTI ID:496769

Chang, L; Bagwell, P F ^[1]

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

We calculate the electrical current flowing through a mesoscopic superconductor{endash}normal-metal{endash}superconductor (SNS) junction coupled to a normal-metal probe. This additional normal terminal models either a scanning tunneling microscope probe or the gate electrode of a three-terminal SNS junction. We find the Josephson current switches between two different values as the probe voltage V is varied. This switching occurs because the Andreev energy levels are populated with an effective electrochemical potential eV. When the probe voltage {vert_bar}eV{vert_bar}{gt}{Delta}, so that all of the Andreev levels are either filled or emptied, we show it is possible to directly measure the {open_quotes}continuum{close_quotes} contribution to the Josephson current. The differential conductance dI/dV at the normal probe can also be used to detect the density of Andreev levels. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 496769
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 18 Vol. 55; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
BOUND STATE
COHERENCE LENGTH
ELECTRIC CURRENTS
ELECTRIC PROBES
ENERGY GAP
ENERGY LEVELS
ENERGY-LEVEL DENSITY
JOSEPHSON JUNCTIONS