Coulomb Gap: How a Metal Film Becomes an Insulator

2000/02/14 by V. Yu. Butko, J. F. DiTusa, P. W. Adams · 3 citations
Engineering · Physics and Astronomy · #Low-power high-performance VLSI design #Quantum and electron transport phenomena #Semiconductor materials and devices #cond-mat.dis-nn #cond-mat.str-el

paper · pdf · doi:10.1103/physrevlett.84.1543

published as Phys. Rev. Lett. 84, 1543 (2000) · 4 figures

openalex publication_date 2000/02/14 · arxiv created 2000/06/01 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01

Abstract

Electron tunneling measurements of the density of states (DOS) in ultrathin Be films reveal that a correlation gap mediates their insulating behavior. In films with sheet resistance R<5000 Omega the correlation singularity appears as the usual perturbative ln(V) zero bias anomaly (ZBA) in the DOS. As R is increased further, however, the ZBA grows and begins to dominate the DOS spectrum. This evolution continues until a nonperturbative |V| Efros-Shklovskii Coulomb gap spectrum finally emerges in the highest R films. Transport measurements of films which display this gap are well described by a universal variable range hopping law R(T) = (h/2e(2))exp(T0/T)(1/2).

Citations

• Universal Linear Density of States for Tunneling into the Two-Dimensional Electron Gas in a Magnetic Field
• Coulomb gap and low temperature conductivity of disordered systems
• Scaling Theory of Localization: Absence of Quantum Diffusion in Two Dimensions

Cited by

• Tunneling into the Normal State ofPr2−xCexCuO4
• Density of states and magnetoconductance of disordered Au point contacts
• Saturation of the Anomalous Hall Effect in Critically Disordered UltrathinCNi3Films