Theory of the Bloch-wave oscillations in small Josephson junctions

Journal Article · Wed May 01 04:00:00 EDT 1985 · J. Low Temp. Phys.; (United States)

DOI:https://doi.org/10.1007/BF00683782· OSTI ID:5597548

Likharev, K K; Zorin, A B

A quantum-statistical theory of the low-temperature behavior of Josephson junctions with very small capacitance C and quasiparticle conductivity G, driven by a small current I(t), is developed. In such junctions the ''secondary'' quantum macroscopic effects (tunneling and interference) are significant for all values of the Josephson phase difference phi, so that new features in the junction dynamics arise, including quantum ''Block-wave'' oscillations. Here the junction dynamics is analyzed in detail starting from a simple macroscopic Hamiltonian. The simplest way to analyze the Bloch-wave oscillations turns out to be a Langevin-type equation for the operator of the junction ''quasicharge'' q. In particular, this equation shows that the frequency f/sub B/ of these oscillations is related by the fundamental equation F/sub B/ = (I-bar-GV-bar)/2e to the dc current I-bar and voltage V-bar. The main effects suppressing or masking the Bloch-wave oscillations can be analyzed using the equation for the density matrix of the system traced over the states of the quasiparticles. This analysis has made it possible to establish the main conditions for the experimental observation of the predicted effects and to present a general picture of the low temperature dynamics of Josephson junctions.

• Research Organization: Department of Physics, Moscow State University, Moscow, USSR
• OSTI ID: 5597548
• Journal Information: J. Low Temp. Phys.; (United States), Journal Name: J. Low Temp. Phys.; (United States) Vol. 59:3; ISSN JLTPA
• Country of Publication: United States
• Language: English

Related Subjects

656101* -- Solid State Physics-- Superconductivity-- General Theory-- (-1987)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CAPACITANCE
DENSITY MATRIX
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
EQUATIONS
FLUCTUATIONS
HAMILTONIANS
JOSEPHSON JUNCTIONS
JUNCTIONS
LANGEVIN EQUATION
MATHEMATICAL OPERATORS
MATRICES
OSCILLATIONS
PHYSICAL PROPERTIES
QUANTUM OPERATORS
QUASI PARTICLES
SUPERCONDUCTING JUNCTIONS
TUNNEL EFFECT
VARIATIONS