{ "id": "2310.12801", "version": "v1", "published": "2023-10-19T14:57:27.000Z", "updated": "2023-10-19T14:57:27.000Z", "title": "Roughness and critical force for depinning at 3-loop order", "authors": [ "Mikhail N. Semeikin", "Kay Joerg Wiese" ], "comment": "24 pages, 17 figures", "categories": [ "cond-mat.dis-nn", "hep-th" ], "abstract": "A $d$-dimensional elastic manifold at depinning is described by a renormalized field theory, based on the Functional Renormalization Group (FRG). Here we analyze this theory to 3-loop order, equivalent to third order in $\\epsilon=4-d$, where $d$ is the internal dimension. The critical exponent reads $\\zeta = \\frac \\epsilon3 + 0.04777 \\epsilon^2 -0.068354 \\epsilon^3 + {\\cal O}(\\epsilon^4)$. Using that $\\zeta(d=0)=2^-$, we estimate $\\zeta(d=1)=1.266(20)$, $\\zeta(d=2)=0.752(1)$ and $\\zeta(d=3)=0.357(1)$. For Gaussian disorder, the pinning force per site is estimated as $f_{\\rm c}= {\\cal B} m^{2}\\rho_m + f_{\\rm c}^0$, where $m^2$ is the strength of the confining potential, $\\cal B$ a universal amplitude, $\\rho_m$ the correlation length of the disorder, and $f_{\\rm c}^0$ a non-universal lattice dependent term. For charge-density waves, we find a mapping to the standard $\\phi^4$-theory with $O(n)$ symmetry in the limit of $n\\to -2$. This gives $f_{\\rm c} = \\tilde {\\cal A}(d) m^2 \\ln (m) + f_{\\rm c}^0 $, with $\\tilde {\\cal A}(d) = -\\partial_n \\big[\\nu(d,n)^{-1}+\\eta(d,n)\\big]_{n=-2}$, reminiscent of log-CFTs.", "revisions": [ { "version": "v1", "updated": "2023-10-19T14:57:27.000Z" } ], "analyses": { "keywords": [ "critical force", "non-universal lattice dependent term", "dimensional elastic manifold", "functional renormalization group", "renormalized field theory" ], "note": { "typesetting": "TeX", "pages": 24, "language": "en", "license": "arXiv", "status": "editable" } } }