Fast classical simulation of qubit-qudit hybrid systems

TL;DR

This paper introduces a block-simulation approach for efficiently simulating hybrid qubit-qudit quantum systems, significantly outperforming previous methods in speed and scalability.

Contribution

It extends block-simulation techniques to qubit-qudit systems, achieving major speed improvements over prior simulators like QuDiet.

Findings

10x to 1000x faster simulation times

Effective for multi-level quantum systems

Applicable to various benchmark circuits

Abstract

Simulating quantum circuits is a computationally intensive task that relies heavily on tensor products and matrix multiplications, which can be inefficient. Recent advancements, eliminate the need for tensor products and matrix multiplications, offering significant improvements in efficiency and parallelization. Extending these optimizations, we adopt a block-simulation methodology applicable to qubit-qudit hybrid systems. This method interprets the statevector as a collection of blocks and applies gates without computing the entire circuit unitary. Our method, a spiritual successor of the simulator QuDiet \cite{Chatterjee_2023}, utilizes this block-simulation method, thereby gaining major improvements over the simulation methods used by its predecessor. We exhibit that the proposed method is approximately 10$\times$ to 1000$\times$ faster than the state-of-the-art simulator for simulating multi-level quantum systems with various benchmark circuits.