Efficient Quantum Circuit Cutting by Neglecting Basis Elements

TL;DR

This paper introduces a method to reduce resource requirements in quantum circuit cutting by neglecting basis elements that pass no information, demonstrated to save up to 33% in execution time.

Contribution

It proposes a novel reduction scheme that identifies and neglects basis elements passing no information, improving efficiency in quantum circuit cutting.

Findings

Up to 33% reduction in wall time achieved.

Method validated on simulators and IBM hardware.

No loss of accuracy observed.

Abstract

Quantum circuit cutting has been proposed to help execute large quantum circuits using only small and noisy machines. Intuitively, cutting a qubit wire can be thought of as classically passing information of a quantum state along each element in a basis set. As the number of cuts increase, the number of quantum degrees of freedom needed to be passed through scales exponentially. We propose a simple reduction scheme to lower the classical and quantum resources required to perform a cut. Particularly, we recognize that for some cuts, certain basis element might pass "no information" through the qubit wire and can effectively be neglected. We empirically demonstrate our method on circuit simulators as well as IBM quantum hardware, and we observed up to 33 percent reduction in wall time without loss of accuracy.