Approximate Quantum Error Correction Revisited: Introducing the Alpha-bit

Understand

We establish that, in an appropriate limit, qubits of communication should be regarded as composite resources, decomposing cleanly into independent correlation and transmission components.

• Because qubits of communication can establish ebits of entanglement, qubits are more powerful resources than ebits.
• We identify a new communications resource, the zero-bit, which is precisely half the gap between them, replacing classical bits by zero-bits makes teleportation asymptotically reversible.
• The decomposition of a qubit into an ebit and two zero-bits has wide-ranging consequences including applications to state merging, the quantum channel capacity, entanglement distillation, quantum identification and remote state preparation.