LEQA: Latency Estimation for a Quantum Algorithm Mapped to a Quantum Circuit Fabric

TL;DR

LEQA is a rapid latency estimation tool for quantum algorithms on quantum fabrics, offering high accuracy and significantly faster performance than detailed scheduling methods, enabling efficient evaluation of quantum circuit performance.

Contribution

LEQA introduces a neighborhood population count-based approach for fast, accurate quantum circuit latency estimation, reducing computation time by up to two orders of magnitude.

Findings

Achieves less than 3% average error in latency estimation.

Provides up to 100x speedup over detailed scheduling methods.

Speedup increases superlinearly with circuit size.

Abstract

This paper presents LEQA, a fast latency estimation tool for evaluating the performance of a quantum algorithm mapped to a quantum fabric. The actual quantum algorithm latency can be computed by performing detailed scheduling, placement and routing of the quantum instructions and qubits in a quantum operation dependency graph on a quantum circuit fabric. This is, however, a very expensive proposition that requires large amounts of processing time. Instead, LEQA, which is based on computing the neighborhood population counts of qubits, can produce estimates of the circuit latency with good accuracy (i.e., an average of less than 3% error) with up to two orders of magnitude speedup for mid-size benchmarks. This speedup is expected to increase superlinearly as a function of circuit size (operation count).