Université Grenoble Alpes, CNRS, Institut Néel, 38000, Grenoble, France.
National Institute of Advanced Industrial Science and Technology (AIST), National Metrology Institute of Japan (NMIJ), 1-1-1 Umezono, Tsukuba, Ibaraki, 305-8563, Japan.
Nat Commun. 2019 Oct 8;10(1):4557. doi: 10.1038/s41467-019-12514-w.
Surface acoustic waves (SAWs) strongly modulate the shallow electric potential in piezoelectric materials. In semiconductor heterostructures such as GaAs/AlGaAs, SAWs can thus be employed to transfer individual electrons between distant quantum dots. This transfer mechanism makes SAW technologies a promising candidate to convey quantum information through a circuit of quantum logic gates. Here we present two essential building blocks of such a SAW-driven quantum circuit. First, we implement a directional coupler allowing to partition a flying electron arbitrarily into two paths of transportation. Second, we demonstrate a triggered single-electron source enabling synchronisation of the SAW-driven sending process. Exceeding a single-shot transfer efficiency of 99%, we show that a SAW-driven integrated circuit is feasible with single electrons on a large scale. Our results pave the way to perform quantum logic operations with flying electron qubits.
表面声波（SAWs）强烈调制压电材料中的浅势。在 GaAs/AlGaAs 等半导体异质结构中，SAWs 可用于在远距离量子点之间传递单个电子。这种转移机制使得 SAW 技术成为通过量子逻辑门电路传输量子信息的有前途的候选者。在这里，我们提出了这种基于 SAW 的量子电路的两个基本构建块。首先，我们实现了一个定向耦合器，允许将飞行电子任意地分成两个传输路径。其次，我们展示了一个触发单电子源，实现了 SAW 驱动发送过程的同步。我们的实验结果表明，通过单次转移效率超过 99%，大规模使用飞行电子实现 SAW 驱动的集成电路是可行的。我们的结果为使用飞行电子量子位执行量子逻辑操作铺平了道路。
