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

Abstract

We observe how an active (i.e., requring $2^n$ parallel control operations) QRAM-like effect $$\sum _{y=0}^{N-1}|y⟩⟨y|\otimes U_{\text{result},{\text{memory}}_y}^y$$ can be realized, as a quantum circuit of depth $O(n+\sqrt{m})$ (where $m$ is the size of the result register) plus the maximum over all~$z$ of the circuit depths of controlled-$U^z$ operations.

5 pages

References in corpus (3)

• Quantum algorithm for solving linear systems of equations
• Quantum random access memory
• Architectures for a quantum random access memory