Single Electron Charging Effects in Insulating and Semiconducting Microstructures

这是一个实验研究项目，专注于纳米制造系统中的低温电子传输，其中电子之间的强静电相互作用导致库仑封锁和单电子充电现象。实验的目的是增加对这种状态下电子传递的微观机制的基本理解，重点是量子效应引入的修饰。这种结构由放置在金属接触电极之间的短绝缘导线组成。目标是了解在这个新系统中观察到的单电子充电效应的起源。着眼于潜在的器件应用，将通过利用绝缘体的一些独特性质来研究提高可以观察到库仑封锁效应的温度范围的不同方法。该项目涉及研究生的研究，是在纳米光刻制造技术的前沿。这个实验项目处理的是单个电子在超小结构中的运动，这种结构是用精细聚焦的电子束通过追踪宽度只有几个原子的图案而制成的。所得结构在低温下对外加电场和磁场表现出显著的响应。这种反应是由量子效应引起的，而量子效应在被研究的结构中只得到很少的理解。检测单个电子运动的能力具有根本的兴趣，并且在技术上具有重要意义，是实现目前设想的最小微电子设备的途径。该项目将采用绝缘纳米结构，这有可能使微型器件在更高的温度下运行。＊＊＊

9313726 Chandrasekhar This is an experimental research program focused on low temperature electron transport in nanofabricated systems in which strong electrostatic interactions between electrons lead to Coulomb blockade and single electron charging phenomena. The experiments are designed to increase fundamental understanding of the microscopic mechanism of electron transport in this regime, with emphasis on modifications introduced by quantum effects. The structures consist of short insulating wires placed between metallic contact electrodes. The goal is to understand the origin of the single electron charging effects that have been observed in this novel system. With an eye to potential device applications, different methods of increasing the temperature range over which the Coulomb blockade effects can be observed will be investigated by exploiting some unique properties of insulators. The project involves graduate students in research that is at the cutting edge of nanolithographic fabrication techniques. %%% This experimental project deals with the motion of individual electrons among ultrasmall structures that are fabricated by tracing patterns only a few atoms in width using a finely focused electron beam. The resulting structures show remarkable responses at low temperatures to applied electric and magnetic fields. The response arises from quantum effects that are only poorly understood in the structures under study. The ability of detection motion of a single electron has fundamental interest and is technologically significant as a route to the smallest microelectronics device currently envisioned. The project will employ insulating nanostructures which have potential for allowing operation of the microdevices at higher temperatures. ***