{ "id": "1001.2984", "version": "v2", "published": "2010-01-18T09:21:16.000Z", "updated": "2010-03-29T14:46:25.000Z", "title": "Many-body localization transition in a lattice model of interacting fermions: statistics of renormalized hoppings in configuration space", "authors": [ "Cecile Monthus", "Thomas Garel" ], "comment": "v2 revised version with new material on real-space correlation (11 pages, 11 figures)", "journal": "Phys. Rev. B 81, 134202 (2010)", "doi": "10.1103/PhysRevB.81.134202", "categories": [ "cond-mat.dis-nn", "cond-mat.str-el" ], "abstract": "We consider the one-dimensional lattice model of interacting fermions with disorder studied previously by Oganesyan and Huse [Phys. Rev. B 75, 155111 (2007)]. To characterize a possible many-body localization transition as a function of the disorder strength $W$, we use an exact renormalization procedure in configuration space that generalizes the Aoki real-space RG procedure for Anderson localization one-particle models [H. Aoki, J. Phys. C13, 3369 (1980)]. We focus on the statistical properties of the renormalized hopping $V_L$ between two configurations separated by a distance $L$ in configuration space (distance being defined as the minimal number of elementary moves to go from one configuration to the other). Our numerical results point towards the existence of a many-body localization transition at a finite disorder strength $W_c$. In the localized phase $W>W_c$, the typical renormalized hopping $V_L^{typ} \\equiv e^{\\bar{\\ln V_L}}$ decays exponentially in $L$ as $ (\\ln V_L^{typ}) \\simeq - \\frac{L}{\\xi_{loc}}$ and the localization length diverges as $\\xi_{loc}(W) \\sim (W-W_c)^{-\\nu_{loc}}$ with a critical exponent of order $\\nu_{loc} \\simeq 0.5$. In the delocalized phase $W