A CNOT gate between multiphoton qubits encoded in two cavities

Understand

Entangling gates between qubits are a crucial component for performing algorithms in quantum computers.

• However, any quantum algorithm must ultimately operate on error-protected logical qubits encoded in high-dimensional systems.
• Typically, logical qubits are encoded in multiple two-level systems, but entangling gates operating on such qubits are highly complex and have not yet been demonstrated.
• Here, we realize a controlled NOT (CNOT) gate between two multiphoton qubits in two microwave cavities.