Identify the hardware modality best suited for large-scale, problem-solving quantum computers

Determine which quantum computing hardware modalities—such as superconducting circuits, trapped ions, neutral Rydberg atoms, photonic qubits, or spin qubits—are best suited to scale to large systems that can solve computationally hard problems, taking into account connectivity, gate fidelities, cycle times, error-correction overheads, and architectural constraints.

Background

The paper reviews rapid advances across leading modalities (superconducting circuits, trapped ions, neutral atoms) and highlights that each has distinct strengths and weaknesses in connectivity, speed, and practicality of syndrome extraction and logical operations.

Despite recent milestones in error correction and demonstrations of logical circuits, the authors stress that the landscape is still shifting and that modalities previously considered less promising (e.g., Rydberg arrays) have emerged strongly, making it premature to declare a dominant path to broadly useful fault-tolerant machines.