International Symposium on Devices, Circuits and Systems (ISDCS)
Implementation of neareast neighbor quantum circuit with low quantum cost
Laxmidhar Biswal, Anirban Bhattachaijee, Sudip Ghosh, Hafizur Rahaman
Abstract
Primary purpose behind this work is to develop a type of quantum gate C2(iZ)/C2(-iZ) derived from unitary quantum gate C2(-I) by finding its 2ndroot. This newly introduced gate is nearest-neighbor compliant with a unit quantum cost. The main objective in deriving this quantum gate C2(iZ)/C2(-iZ) is to generate low cost MCT gates which eventually produces cost optimized NNC free reversible circuits. For systematic mapping and a fair comparison with prior works, we formed a quantum gate library that includes CNOT, NOT, H, CH, C2(-I) and C2(iZ)/C2(-iZ) gates. A mapping algorithm including the complete gate library is proposed alongwith necessary mathematical proofs. Using the gate library, we show significant cost savings is achievable over the state-of-the-art approaches, when mapping n-control Toffoli gates and chosen benchmark functions.