Device Architecture for Coupling Spin Qubits via an Intermediate Quantum State

Electron spins confined to quantum dots are currently of interest as a scalable platform for constructing a quantum computer, although here implementing a fast, high-fidelity gate to entangle qubits remains a challenge. The authors demonstrate a device architecture that enables coupling of qubits via a mediating quantum state, realized using a many-electron quantum dot. This platform potentially enables medium-range entangling gates in spin-based qubit architectures, and offers the prospect of scaling spin qubits beyond linear arrays.