2003/11/21 by I. S. Beloborodov, A. V. Lopatin, G. Schwiete +2
Physics and Astronomy · #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #Theoretical and Computational Physics #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.70.073404
published as Phys. Rev. B 70, 073404 (2004) · 4 pages, 1 figure
arxiv created 2003/11/21 · openalex publication_date 2004/08/24 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We investigate the effect of Coulomb interactions on the tunneling density of states (DOS) of granular metallic systems at the onset of Coulomb blockade regime in two and three dimensions (d=2,3). Using the renormalization group technique we derive the analytical expressions for the DOS as a function of temperature T and energy \ensuremathε. We show that samples with the bare intergranular tunneling conductance gT0 less than the critical value gTC=(1∕2\ensuremathπd)ln(EC∕\ensuremathδ), where EC and \ensuremathδ are the charging energy and the mean energy level spacing in a single grain, respectively, are insulators with a hard gap in the DOS at temperatures T\ensuremath→0. In 3d systems the critical conductance gTC separates insulating and metallic phases at zero temperature, whereas in the granular films gTC separates insulating states with the hard (at gT0<gTC) and soft (at gT0>gTC) gaps. The gap in the DOS begins to develop at temperatures T*\ensuremath∼ECgT0\phantom\rule0.2em0exexp(\ensuremath-2\ensuremathπdgT0) and reaches the value \ensuremathΔ\ensuremath∼T* at T\ensuremath→0.