NIRT: Field Effect Switching of Molecular Charge Configurations for QCA

NIRT：QCA分子电荷组态的场效应转换这项建议是对NSF 03-043，NIRT类纳米科学与工程倡议的响应。单分子量子点细胞自动机(QCA)细胞是通过设计具有多个氧化还原中心的分子来实现的。分子电荷在氧化还原中心之间的分布代表二元信息。QCA行为的关键是，一个由邻近分子引起的局部电场，即“驱动场”，以一种非线性的方式改变了另一个分子的电荷构型。论证分子电荷组态的场效应转换是本研究的重点。使用具有分子分辨率的扫描探针对这项研究至关重要。我们的策略是使用混合价片段的化学变化来消除在解释我们的结果时的任何含糊之处。将电子设备缩小到单分子水平可能需要放弃使用晶体管来表示二进制信息的概念。这项研究正在探索一种不同的方法--使用分子，分子可以存在于两种不同的配置中来编码二进制信息。这种方法被称为量子点细胞自动机(QCA)，已经在更大的长度范围内使用小金属点进行了演示。我们正在研究分子QCA实现的一个方面--通过邻近分子的影响来切换一个分子。这个问题是分子QCA概念的核心，如果成功，它将使器件密度比硅晶体管可能的密度大100万倍。

NIRT: Field-effect switching of molecular charge configuration for QCAThis proposal was received in response to Nanoscale Science and Engineering initiative, NSF 03-043, category NIRT. Single-molecule quantum-dot cellular automata (QCA) cells are realized by designing molecules with multiple redox centers. The distribution of molecular charge among the redox centers represents binary information. The key to QCA behavior is that a local electric field, the "driver field," due to a neighboring molecule alters the charge configuration of another molecule in a nonlinear way. Demonstration of field-effect switching of molecular charge configuration is the focus of the proposed research. The use of scanning probes with molecular resolution is crucial to this investigation. Our strategy is to use chemical variation of mixed-valence pieces to remove any ambiguities in the interpretation of our results. Shrinking electronic devices to the single-molecule level may require abandoning the notion of using transistors to represent binary information. The research is exploring a different approach - using molecules, which can exist in two different configurations to encode the binary information. This approach, called quantum-dot cellular automata (QCA), has already been demonstrated at a larger length scale using small metal dots. We are investigating one aspect of a molecular QCA implementation - the switching of one molecule by the influence of a neighboring molecule. This problem is at the heart of the molecular QCA concept, which if successful would enable device densities perhaps a million times greater than those possible with silicon transistors.