Note on (active-)QRAM-style data access as a quantum circuit

Tore Vincent Carstens, Dirk Oliver Theis

We observe how an active (i.e., requring $2^n$ parallel control operations) QRAM-like effect $$\sum _{y=0}^{N-1}|y⟩⟨y|\otimes U_{\text{result},{\text{memory}}_y}^y$$ ca…