Shuttling a single charge across a one-dimensional array of silicon quantum dots

TL;DR

This paper demonstrates the successful shuttling of single electrons across a linear array of nine silicon quantum dots within 50 nanoseconds, showcasing a method for quantum state transfer beyond nearest neighbors.

Contribution

It introduces a practical method for physically transporting single electrons across large silicon quantum dot arrays, enabling long-range connectivity in quantum computing architectures.

Findings

Single electron shuttling achieved in ~50 ns

Parallel shuttling of 2 and 3 electrons demonstrated

Physical transport feasible in large silicon arrays

Abstract

Significant advances have been made towards fault-tolerant operation of silicon spin qubits, with single qubit fidelities exceeding 99.9%, several demonstrations of two-qubit gates based on exchange coupling, and the achievement of coherent single spin-photon coupling. Coupling arbitrary pairs of spatially separated qubits in a quantum register poses a significant challenge as most qubit systems are constrained to two dimensions (2D) with nearest neighbor connectivity. For spins in silicon, new methods for quantum state transfer should be developed to achieve connectivity beyond nearest-neighbor exchange. Here we demonstrate shuttling of a single electron across a linear array of 9 series-coupled Si quantum dots in ~50 ns via a series of pairwise interdot charge transfers. By progressively constructing more complex pulse sequences we perform parallel shuttling of 2 and 3 electrons at a time through the 9-dot array. These experiments establish that physical transport of single electrons is feasible in large silicon quantum dot arrays.