Disorder Driven Lock-In Transitions of CDWs and Related Structures

dc.creatorNattermann, T.
dc.creatorEmig, T.
dc.creatorBogner, S.
dc.date1999-08-25
dc.date.accessioned2026-07-07T03:14:20Z
dc.date.available2026-07-07T03:14:20Z
dc.descriptionThermal fluctuations are known to play an important role in low-dimensional systems which may undergo incommensurate-commensurate or (for an accidentally commensurate wavevector) lock-in transitions. In particular, an intermediate floating phase with algebraically decaying correlations exists only in D=2 dimensions, whereas in higher dimensions most features of the phase diagram are mean-field like. Here we will show, that the introduction of frozen-in disorder leads to strong fluctuation effects even in D<4 dimensions. For commensurate wavevectors the lattice pinning potential dominates always over weak impurity pinning if p \le p_c=6/π(D=3), where p denotes the degeneracy of the commensurate phase. For larger p a disorder driven continuous transition between a long-range ordered locked-in phase and quasi-long-range ordered phase, dominated by impurity pinning, occurs. Critical exponents of this transition, which is characterized by a zero temperature fixed point, are calculated within an expansion in 4-D. The generalization to incommensurate wavevectors will be discussed. If the modulation in the quasi-long-range ordered phase has hexagonal symmetry, as e.g.for flux-line lattices, the algebraic decay is non-universal and depends on the Poisson ratio of the elastic constants. Weakly driven transport is dominated by thermally activated creep in both phases, but with different creep exponents.
dc.description5 pages, 1 figure; to appear in the proceedings of ECRYS-99
dc.identifierhttps://arxiv.org/abs/cond-mat/9908353
dc.identifierhttp://arxiv.org/abs/cond-mat/9908353
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/29634
dc.subjectStatistical Mechanics
dc.titleDisorder Driven Lock-In Transitions of CDWs and Related Structures
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