Department of Physics, California State University, Bakersfield, CA 93311, USA.
J Phys Condens Matter. 2011 Feb 2;23(4):045301. doi: 10.1088/0953-8984/23/4/045301. Epub 2011 Jan 12.
A two-dimensional δ-potential Kronig-Penney model for quasi-one-dimensional (Q1D) disordered systems is used to study analytically the influence of a constant electric field on the inverse localization length (LL). Based on the Green's function formalism we have calculated LL as a function of the incoming energy E, electric field F, length L of the Q1D sample, number of modes M in the transverse direction and the amount of disorder w. We show that, for large L in Q1D systems, states are weakly localized, i.e. we deal with power-law localization. With increasing electric field in Q1D mesoscopic systems a transition from exponential to a power-law behavior takes place, as in 1D systems. We note that the graphs showing the inverse LL change significantly with increasing F (for fixed M) rather than with increasing M (for fixed F). We also show that the graphs representing the ratio of the corresponding localization length without and with electric field collapse for all modes M into a universal curve in the Q1D strip model.
我们使用二维δ势 Kronig-Penney 模型来研究准一维（Q1D）无序系统，对恒定电场对逆局域化长度（LL）的影响进行了分析。基于格林函数形式主义，我们计算了 LL 作为输入能量 E、电场 F、Q1D 样品长度 L、横向模式数 M 和无序量 w 的函数。我们表明，在 Q1D 系统中，对于较大的 L，状态是弱局域的，即我们处理的是幂律局域化。随着 Q1D 介观系统中电场的增加，会从指数行为转变为幂律行为，就像在 1D 系统中一样。我们注意到，随着 F 的增加（对于固定的 M）而不是随着 M 的增加（对于固定的 F），表示逆 LL 变化的图形会发生显著变化。我们还表明，在 Q1D 条带模型中，代表无电场和有电场时相应局域化长度的比值的图形对于所有模式 M 都合并为一个通用曲线。
