Dresden 2006 – wissenschaftliches Programm

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TT: Tiefe Temperaturen

TT 32: Transport: Quantum Coherence and Quantum Information Systems - Part 2

TT 32.10: Vortrag

Donnerstag, 30. März 2006, 16:30–16:45, HSZ 304

Macroscopic quantum dynamics in one-dimensional Josephson junction arrays — •Mikhail V. Fistul — Theoretische Physik III, Ruhr-Universität Bochum, D-44801 Bochum Germany

I present a theoretical study of the current-voltage characteristics (I-V curves) of one-dimensional Josephson junction arrays containing small Josephson junctions. The transport properties of such a system are determined by the dynamics of both "classical" degrees of freedom, i.e. the phases of superconducting order parameter in leads, and the macroscopic quantum degrees of freedom, i.e. the Josephson phases of intrinsic junctions. I will show that at low temperature and in a particular regime characterizing by a large damping in leads and a small damping in an internal part of the system, the I-V curves are determined by the quantum correlations of Josephson phases, and therefore, it allows to obtain a direct information on the macroscopic quantum dynamics, i.e. macroscopic quantum tunneling of vortices or Coulomb blockade of Cooper pairs. In the framework of this analysis the Cooper pair cotunneling regime [1] and the superconductor-insulator transition [2] in Josephson junction arrays will be discussed.

[1] S. V. Lotkhov, S. A. Bogoslovsky, A. B. Zorin, and J. Niemeyer, Phys. Rev. Lett. 91, 197002 (2003)

[2] E. Chow, P. Delsing, and D. B. Haviland, Phys. Rev. Lett. 81, 204 (1998)