Approximate Reversible Circuits for NISQ-Era Quantum Computers

TL;DR

This paper explores the use of approximate reversible circuits in NISQ-era quantum computers, demonstrating that they can outperform exact circuits in noisy environments by achieving lower error rates.

Contribution

It introduces a novel approach to quantum circuit synthesis focusing on approximation under resource constraints, contrasting traditional minimization strategies.

Findings

Approximate circuits can perform computations with fewer errors under noise.

Experiments show approximate circuits outperform exact ones in noisy simulations.

Resource-limited approximate circuits are viable for NISQ quantum computing.

Abstract

The synthesis approaches for quantum circuits typically aim at minimizing the number of lines or gates. Given the tight restrictions on those logical resources in physical implementations, we propose to view the problem fundamentally different: Given noisy gates and a fixed number of lines, how can we use them to perform a computation as precisely as possible? In this paper we show approximate circuits can be deployed for computations with limited resources. Performing experiments on a QC simulator, we show that under the influence of noise, approximate circuits can have lower error-rates than exact circuits.