Regensburg 2002 – wissenschaftliches Programm

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TT: Tiefe Temperaturen

TT 4: Supraleitung: Massivmaterialien, Bandleiter, Pinning, Vortexdynamik, Transporteigenschaften, Korngrenzen

TT 4.12: Vortrag

Montag, 11. März 2002, 17:15–17:30, H18

Probability Distributions of Line Lattices in Random Media from the 1D Bose Gas — •Thorsten Emig¹ and Mehran Kardar^2,3 — ¹Institut für Theoretische Physik, Universität zu Köln, Zülpicher Strasse 77, 50937 Köln — ²Physics Department, Massachusetts Institute of Technology, Cambridge, MA 02139, USA — ³Institute for Theoretical Physics, University of California, Santa Barbara, CA 93106, USA

The statistical properties of a two dimensional lattice of elastic lines in a random medium are studied using the Bethe ansatz. We present a novel mapping of the dilute random line lattice onto the weak coupling limit of a pure Bose gas with delta-function interactions [1,2]. Using this mapping, we calculate the cumulants of the free energy in the dilute limit exactly. The relation between density and displacement correlation functions in the two models is examined and compared with existing results from renormalization group and variational ansätze.

Recently, the statistics of line lattices was studied experimentally on a flux line lattice oriented parallel to a thin micrometer-sized film of 2H-NbSe₂ [3], providing a nice tool to test our theory.

[1] T. Emig, M. Kardar, Phys. Rev. Lett. 85, 2176 (2000). [2] T. Emig, M. Kardar, Nucl. Phys. B 604, 479 (2001). [3] C. A. Bolle et al., Nature 399, 43 (1999).