A Model for Unitary Black Hole Evaporation

We describe a model for unitary black hole evaporation with no information loss in terms of a quantum computation. We assume that there is a fine tuned interaction between the qubits of the black hole Bell states which is the inverse of premeasurement. Evaporation is unitary due to a projection on the black hole state at the end of each computation whereas information comes out of the black hole by teleportation. The model requires only four operations; the qubit interactions, the Hadamard and CNOT gates and the projection which is nonunitary. The model is a concrete quantum computation that realizes the final black hole state idea with some modifications.