Department of Materials Science and Engineering, University of Utah, Salt Lake City, UT 84112, USA.
Nanoscale. 2011 Oct 5;3(10):4201-5. doi: 10.1039/c1nr10489f. Epub 2011 Aug 25.
Quantum cellular automata (QCA) is an innovative approach that incorporates quantum entities in classical computation processes. Binary information is encoded in different charge states of the QCA cells and transmitted by the inter-cell Coulomb interaction. Despite the promise of QCA, however, it remains a challenge to identify suitable building blocks for the construction of QCA. Graphene has recently attracted considerable attention owing to its remarkable electronic properties. The planar structure makes it feasible to pattern the whole device architecture in one sheet, compatible with the existing electronics technology. Here, we demonstrate theoretically a new QCA architecture built upon nanopatterned graphene quantum dots (GQDs). Using the tight-binding model, we determine the phenomenological cell parameters and cell-cell response functions of the GQD-QCA to characterize its performance. Furthermore, a GQD-QCA architecture is designed to demonstrate the functionalities of a fundamental majority gate. Our results show great potential in manufacturing high-density ultrafast QCA devices from a single nanopatterned graphene sheet.
量子细胞自动机（QCA）是一种创新的方法，它将量子实体纳入经典计算过程中。二进制信息被编码在 QCA 单元的不同电荷状态中，并通过单元间库仑相互作用传输。然而，尽管 QCA 有很大的前景，但要找到适合构建 QCA 的构建块仍然是一个挑战。石墨烯由于其显著的电子特性而引起了相当大的关注。其平面结构使得在一张薄片上形成整个器件结构成为可能，与现有的电子技术兼容。在这里，我们理论上展示了一种基于纳米图案化石墨烯量子点（GQD）的新型 QCA 架构。我们使用紧束缚模型确定 GQD-QCA 的唯象单元参数和单元-单元响应函数，以表征其性能。此外，还设计了一种 GQD-QCA 架构来演示基本多数门的功能。我们的结果表明，从单个纳米图案化石墨烯片制造高密度超快 QCA 器件具有很大的潜力。
