Slow dynamics of electron glasses: The role of disorder

Article

关键词: ULTRATHIN FILMS;    COULOMB GAP;    LOCALIZATION;    RELAXATION;    CONDUCTIVITY;    ABSORPTION;    BEHAVIOR;    SYSTEMS;    MEMORY;    EDGE;   

DOI  :  10.1103/PhysRevB.95.134203

来源: SCIE

【 摘 要 】

We examine in this work the role of disorder in contributing to the sluggish relaxation observed in intrinsic electron glasses. Our approach is guided by several empirical observations: First and foremost, Anderson localization is a pre-requisite for observing these nonequilibrium phenomena. Secondly, sluggish relaxation appears to favor Anderson insulators with relatively large Fermi energies (hence proportionally large disorder). These observations motivated us to consider a way to measure the underlying disorder in a realistic Anderson insulator. Optical studies using a series of amorphous indium oxide (In-x O) establish a simple connection between carrier concentration and the disorder necessary to approach themetal-insulator transition from the insulating side. This is used to estimate the typical magnitude of the quenched potential fluctuation in the electron-glass phase of this system. The implications of our findings on the slow dynamics of Anderson insulators are discussed. In particular, the reason for the absence of a memory dip and the accompanying electron-glass effects in lightly-doped semiconductors emerges as a natural consequence of their weak disorder.

【 授权许可】

Free