Directed polymer in a random medium of dimension 1+3 : multifractal properties at the localization/delocalization transition
| dc.creator | Monthus, Cecile | |
| dc.creator | Garel, Thomas | |
| dc.date | 2007-01-29 | |
| dc.date.accessioned | 2026-07-07T08:05:44Z | |
| dc.date.available | 2026-07-07T08:05:44Z | |
| dc.description | We consider the model of the directed polymer in a random medium of dimension 1+3, and investigate its multifractal properties at the localization/delocalization transition. In close analogy with models of the quantum Anderson localization transition, where the multifractality of critical wavefunctions is well established, we analyse the statistics of the position weights $w_L(\vec r)$ of the end-point of the polymer of length $L$ via the moments $Y_q(L) = \sum_{\vec r} [w_L(\vec r)]^q$. We measure the generalized exponents $τ(q)$ and $\tilde τ(q)$ governing the decay of the typical values $Y^{typ}_q(L) = e^{\bar{\ln Y_q(L)}} \sim L^{- τ(q)} $ and disorder-averaged values $\bar{Y_q(L)} \sim L^{- \tilde τ(q)} $ respectively. To understand the difference between these exponents, $ τ(q) \neq \tilde τ(q)$ above some threshold $q>q_c \sim 2$, we compute the probability distributions of $y=Y_q(L)/Y^{typ}_q(L) $ over the samples : we find that these distributions becomes scale invariant with a power-law tail $1/y^{1+x_q}$. These results thus correspond to the Ever-Mirlin scenario [Phys. Rev. Lett. 84, 3690 (2000)] for the statistics of Inverse Participation Ratios at the Anderson localization transitions. Finally, the finite-size scaling analysis in the critical region yields the correlation length exponent $ν\sim 2$. | |
| dc.description | 10 pages, 15 figures | |
| dc.identifier | https://arxiv.org/abs/cond-mat/0701699 | |
| dc.identifier | http://arxiv.org/abs/cond-mat/0701699 | |
| dc.identifier | Phys. Rev. E 75, 051122 (2007) | |
| dc.identifier | doi:10.1103/PhysRevE.75.051122 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/130375 | |
| dc.subject | Disordered Systems and Neural Networks | |
| dc.subject | Probability | |
| dc.title | Directed polymer in a random medium of dimension 1+3 : multifractal properties at the localization/delocalization transition | |
| dc.type | text |