Definition: Ordered streaming access

The accessible input is an arbitrary joint state on an ordered list of carriers $q_1,\dots ,q_n$. A passive supplier retains the undelivered carriers and transfers them, one at a time, on request in that order.

The supplier performs no decoding, measurement, or state-dependent selection. The laboratory may pause delivery but may not return intermediate quantum data to the supplier, use another quantum buffer, or export a quantum output before completion. The target quantum output is returned only at the end.