End-to-end cost of a logical T gate implemented via cultivated magic states

Perform end-to-end simulations of a logical T gate implemented by gate teleportation using cultivated T|+> states, including parallel production attempts, real-time retries upon postselection failures, lattice-surgery attachment to the target logical qubit, and real-time Clifford corrections, to determine the actual spacetime cost and verify whether it is approximately twice the cost of a lattice-surgery CNOT of comparable reliability.

Background

The paper benchmarks only the preparation (cultivation) of T states, not their consumption in gate teleportation. While historical data suggest that producing a T state may be comparable to a CNOT of similar reliability, the full logical T gate involves additional steps that could change costs.

A definitive assessment requires end-to-end simulation of the whole gate-teleportation procedure (including routing, attachment, classical feedback), which the authors identify as a major next step and note they cannot confirm without such a simulation.