How statement and proof provenance work
The first chip identifies the source of the statement or construction; the second identifies the source of its local proof or verification.
- Literature-sourced: the exact statement appears in a cited source; only wording and notation differ.
- AI-adapted: a semantically identical restatement of literature-sourced material, modulo indexing, notation, and boundary cases adopted by the library.
- AI-generated: a genuinely novel statement formulated by AI, with no source for the claim itself.
These labels describe origin, not correctness: citations and verification chips remain separate evidence.
Entanglement-assisted capacity of a noiseless qubit
Example
For the identity channel on a qubit, the entanglement-assisted classical capacity is nats per use, or two classical bits per transmitted qubit. A shared Bell pair and the four-message dense-coding protocol attain the value.
Facts & Assumptions
Given: The noiseless identity channel and prior shared entanglement.
Complementary channels and coherent information: for a purification.
The maximally mixed state maximizes finite quantum entropy: for a qubit, , with equality at .
The Bell vectors: the four Bell vectors form an orthonormal basis of .
Dense-coding correctness and resources: the four Pauli encodings on one half of a shared Bell pair produce the four orthogonal Bell states, which Bob distinguishes with zero error using one transmitted qubit.
Verification
For any qubit input , the identity channel leaves its purification pure. Hence and , so [F2] gives . By [F1] and [F3], .
For a maximally entangled Bell pair, Alice's four Pauli choices produce the four orthogonal Bell states by [F4]–[F5]. Bob's Bell-basis measurement identifies the message without error, so four messages are sent per channel use and the rate is . This attains the capacity computed in step 1.1.
Depends on
- Additive entanglement-assisted classical capacity formula
- Dense-coding correctness and resources
- The Bell vectors
- The maximally mixed state maximizes finite quantum entropy
- Complementary channels and coherent information
- Finite-dimensional von Neumann entropy
- Complex spectral theorem: a normal endomorphism of a finite-dimensional complex inner product space has an orthonormal eigenbasis, and conversely
Used by
Nothing in the library uses this result yet.
Dependency tree · two levels
55 results within two dependency steps of this one, each drawn at its shortest distance from it. An arrow runs from a result to what uses it, so the chart reads left to right and ends at this result, which carries a heavier outline. Every node is a link to that result. Click elsewhere on the chart to enlarge it.
Sources
- John Watrous, The Theory of Quantum Information, §6.3.1 and Theorem 8.41 (standard reference, not scraped)
- Bennett, Shor, Smolin, and Thapliyal, Entanglement-assisted capacity of a quantum channel and the reverse Shannon theorem, §II (standard reference, not scraped)