An Efficient Method for Quantum Circuit Placement Problem on a 2-D Grid

Abstract

This work-in-progress report proposes an efficient method to solve “quantum circuit placement problems” which are considered explicitly or implicitly when we convert an arbitrary quantum circuit into a nearest neighbor (NN) compliant circuit. A quantum circuit placement problem is to find as few SWAP gates as possible to convert a given initial qubit placement into a desired qubit placement. In the existing methods, the problem is solved by an ILP formulation or an A* search algorithm; the existing approaches may not be scalable for large quantum circuits. Thus, we are considering a more efficient method to solve the problem; our method tries to apply only SWAP gates such that do not have any bad effect on the desired movement of all the qubits. We also report a preliminary experimental result to show how our method improve the A* search algorithm which is used to generate NN compliant circuits.