Abstract/Summary

This paper proposes a quantum multiply-accumulator circuit (QMAC), which can perform the calculation on conventional integers faster than its classical counterpart. Whereas classically applying a multiply–adder (MAC) n times to k bit integers would require O(n log k) parallel steps, the hybrid QMAC needs only O(n+k) steps for the exact result and O(n+log k) steps for an approximate result. The proposed circuit could potentially be embedded in a conventional computer architecture as a quantum device or accelerator, enabling a wide range of applications to execute faster.