Quantum and classical resonant escapes of a strongly driven Josephson junction

Journal Article · Thu Apr 01 00:00:00 EDT 2010 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PHYSREVB.81.144518· OSTI ID:21366720

Yu, H F; Zhu, X B; Peng, Z H; Cao, W H; Cui, D J; Tian, Ye; Chen, G H; Zheng, D N; Jing, X N; Lu, Li; Zhao, S P; Siyuan, Han ^[1]

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1. Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

The properties of phase escape in a dc superconducting quantum interference device (SQUID) at 25 mK, which is well below quantum-to-classical crossover temperature T{sub cr}, in the presence of strong resonant ac driving have been investigated. The SQUID contains two Nb/Al-AlO{sub x}/Nb tunnel junctions with Josephson inductance much larger than the loop inductance so it can be viewed as a single junction having adjustable critical current. We find that with increasing microwave power W and at certain frequencies nu and nu/2, the single primary peak in the switching current distribution, which is the result of macroscopic quantum tunneling of the phase across the junction, first shifts toward lower bias current I and then a resonant peak develops. These results are explained by quantum resonant phase escape involving single and two photons with microwave-suppressed potential barrier. As W further increases, the primary peak gradually disappears and the resonant peak grows into a single one while shifting further to lower I. At certain W, a second resonant peak appears, which can locate at very low I depending on the value of nu. Analysis based on the classical equation of motion shows that such resonant peak can arise from the resonant escape of the phase particle with extremely large oscillation amplitude resulting from bifurcation of the nonlinear system. Our experimental result and theoretical analysis demonstrate that at T<<T{sub cr}, escape of the phase particle could be dominated by classical process, such as dynamical bifurcation of nonlinear systems under strong ac driving.

• OSTI ID: 21366720
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Vol. 81, Issue 14; Other Information: DOI: 10.1103/PhysRevB.81.144518; (c) 2010 The American Physical Society; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALUMINIUM
ALUMINIUM OXIDES
AMPLITUDES
BIFURCATION
CRITICAL CURRENT
DISTRIBUTION
EQUATIONS OF MOTION
INDUCTANCE
JOSEPHSON JUNCTIONS
MICROWAVE RADIATION
NIOBIUM
OSCILLATIONS
PARTICLES
PHOTONS
SQUID DEVICES
TEMPERATURE RANGE 0000-0013 K
TUNNEL EFFECT
ALUMINIUM COMPOUNDS
BOSONS
CHALCOGENIDES
CURRENTS
DIFFERENTIAL EQUATIONS
ELECTRIC CURRENTS
ELECTRICAL PROPERTIES
ELECTROMAGNETIC RADIATION
ELECTRONIC EQUIPMENT
ELEMENTARY PARTICLES
ELEMENTS
EQUATIONS
EQUIPMENT
FLUXMETERS
MASSLESS PARTICLES
MEASURING INSTRUMENTS
METALS
MICROWAVE EQUIPMENT
OXIDES
OXYGEN COMPOUNDS
PARTIAL DIFFERENTIAL EQUATIONS
PHYSICAL PROPERTIES
RADIATIONS
REFRACTORY METALS
SUPERCONDUCTING DEVICES
SUPERCONDUCTING JUNCTIONS
TEMPERATURE RANGE
TRANSITION ELEMENTS