Coulomb gap: How a metal film becomes an insulator

被引：92

作者：

Butko, VY ^{[1
]}

DiTusa, JF ^{[1
]}

Adams, PW ^{[1
]}

机构：

[1] Louisiana State Univ, Dept Phys & Astron, Baton Rouge, LA 70806 USA

来源：

PHYSICAL REVIEW LETTERS | 2000年 / 84卷 / 07期

关键词：

D O I：

10.1103/PhysRevLett.84.1543

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

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 Ohm 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(T-0/T)(1/2).

引用

页码：1543 / 1546

页数：4