Logic gates at the surface code threshold: Superconducting qubits poised for fault-tolerant quantum computing

Understand

A quantum computer can solve hard problems - such as prime factoring, database searching, and quantum simulation - at the cost of needing to protect fragile quantum states from error.

• Quantum error correction provides this protection, by distributing a logical state among many physical qubits via quantum entanglement.
• Superconductivity is an appealing platform, as it allows for constructing large quantum circuits, and is compatible with microfabrication.
• For superconducting qubits the surface code is a natural choice for error correction, as it uses only nearest-neighbour coupling and rapidly-cycled entangling gates.