Quantum mechanics of a macroscopic variable: The phase difference of a Josephson Junction

Journal Article · Fri Feb 26 00:00:00 EST 1988 · Science (Washington, D.C.); (USA)

DOI:https://doi.org/10.1126/science.239.4843.992· OSTI ID:5608123

Clarke, J; Cleland, A N; Devoret, M H; Esteve, D; Martinis, J M ^[1]

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1. Univ. of California, Berkeley (USA)

Experiments to investigate the quantum behavior of a macroscopic degree of freedom, namely the phase difference across a Josephson tunnel junction, are described. The experiments involve measurements of the escape rate of the junction from its zero voltage stage. Low temperature measurements of the escape rate for junctions that are either nearly undamped or moderately damped agree very closely with predictions for macroscopic quantum tunneling, with no adjustable parameters. Microwave spectroscopy reveals quantized energy levels in the potential well of the junction in excellent agreement with quantum-mechanical calculations. The system can be regarded as a macroscopic nucleus with wires. 29 refs., 7 figs., 1 tab.

• OSTI ID: 5608123
• Journal Information: Science (Washington, D.C.); (USA), Journal Name: Science (Washington, D.C.); (USA) Vol. 239; ISSN SCIEA; ISSN 0036-8075
• Country of Publication: United States
• Language: English

Related Subjects

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657002 -- Theoretical & Mathematical Physics-- Classical & Quantum Mechanics
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CLASSICAL MECHANICS
COOPER PAIRS
CRITICAL CURRENT
CURRENTS
DAMPING
DATA
DEGREES OF FREEDOM
DESIGN
DIFFERENTIAL EQUATIONS
ELECTRIC CONDUCTIVITY
ELECTRIC CURRENTS
ELECTRICAL PROPERTIES
ENERGY LEVELS
EQUATIONS
EQUATIONS OF MOTION
EXPERIMENTAL DATA
INFORMATION
JOSEPHSON EFFECT
JOSEPHSON JUNCTIONS
JUNCTIONS
MECHANICS
NUMERICAL DATA
OSCILLATIONS
PARTIAL DIFFERENTIAL EQUATIONS
PHYSICAL PROPERTIES
QUANTUM MECHANICS
SPECTROSCOPY
SUPERCONDUCTING JUNCTIONS
SUPERCONDUCTORS
TUNNEL EFFECT
VOLTAGE DROP