GALA-n: Generic Architecture of Layout-Aware n-Bit Quantum Operators for Cost-Effective Realization on IBM Quantum Computers

TL;DR

This paper introduces GALA-n, a cost-effective, layout-aware architecture for n-bit quantum operators on IBM quantum computers, reducing quantum cost compared to traditional methods.

Contribution

The paper presents a novel GALA-n architecture and a new quantum cost formula, improving transpilation efficiency for n-bit quantum operators on IBM hardware.

Findings

GALA-n operators have lower transpilation quantum cost than conventional methods.

The new formula accurately calculates native gates, SWAP gates, and circuit depth.

GALA-n improves cost-efficiency for n-bit quantum operations.

Abstract

A generic architecture of n-bit quantum operators is proposed for cost-effective transpilation, based on the layouts and the number of n neighbor physical qubits for IBM quantum computers, where n >= 3. This proposed architecture is termed "GALA-n quantum operator". The GALA-n quantum operator is designed using the visual approach of the Bloch sphere, from the visual representations of the rotational quantum operations for IBM native gates (square root of X, X, RZ, and CNOT). In this paper, we also proposed a new formula for the quantum cost, which calculates the total numbers of native gates, SWAP gates, and the depth of the final transpiled quantum circuits. This formula is termed the "transpilation quantum cost". After transpilation, our proposed GALA-n quantum operator always has a lower transpilation quantum cost than that of conventional n-bit quantum operators, which are mainly constructed from costly n-bit Toffoli gates.