# Sound-driven single-electron transfer in a circuit of coupled quantum rails

## TL;DR

This paper demonstrates key components for a quantum circuit using surface acoustic waves to transfer single electrons with high efficiency, enabling potential quantum logic operations with flying electron qubits.

## Contribution

It introduces a directional coupler and a triggered single-electron source for SAW-driven quantum circuits, achieving over 99% transfer efficiency.

## Key findings

- Directional coupler for electron path partitioning
- Triggered single-electron source with high synchronization
- Single-electron transfer efficiency exceeds 99%

## Abstract

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.