Designs for a two-dimensional Si quantum dot array with spin qubit addressability

TL;DR

This paper proposes a practical two-dimensional silicon quantum dot array design for spin qubits, enabling efficient qubit connectivity and addressability, and demonstrates its advantage in executing quantum algorithms compared to 1D arrays.

Contribution

The paper introduces a novel 3x3 silicon quantum dot array design with addressability and connectivity, and proposes a scalable structure with ferromagnetic gates for larger arrays.

Findings

3x3 array executes four-qubit Grover's algorithm more efficiently than 1D arrays

Design ensures qubit addressability and connectivity in 2D arrays

Proposes a scalable structure with ferromagnetic gates for larger arrays

Abstract

Electron spins in Si are an attractive platform for quantum computation, backed with their scalability and fast, high-fidelity quantum logic gates. Despite the importance of two-dimensional integration with efficient connectivity between qubits for medium- to large-scale quantum computation, however, a practical device design that guarantees qubit addressability is yet to be seen. Here, we propose a practical 3 x 3 quantum dot device design and a larger-scale design as a longer-term target. The design goal is to realize qubit connectivity to the four nearest neighbors while ensuring addressability. We show that a 3 x 3 quantum dot array can execute four-qubit Grover's algorithm more efficiently than the one-dimensional counterpart. To scale up the two-dimensional array beyond 3 x 3, we propose a novel structure with ferromagnetic gate electrodes. Our results showcase the possibility of medium-sized quantum processors in Si with fast quantum logic gates and long coherence times.