Classical and Quantum Simulations via Molecular Dynamics

Tran Doan Huan

Jincheng Zhang

This paper explores the potential of a hybrid quantum-classical simulation approach to accelerate the simulation of complex molecular systems. Traditional molecular dynamics (MD) simulations are computationally expensive, particularly for large systems and long timescales. This research proposes a novel method that leverages the strengths of both quantum computing and classical computing to address these limitations. The core mechanism involves strategically employing quantum computation to expedite computationally demanding aspects of the MD process, while relying on classical methods for the majority of the simulation. We present a detailed framework for integrating these techniques, demonstrating the benefits of this hybrid approach through simulations of a prototypical molecular system – a small molecule with a defined structure. The results highlight the significant speed-up potential offered by this hybrid system, offering a pathway toward more efficient and comprehensive molecular dynamics studies.

Jincheng Zhang

This research explores the potential of quantum simulation for tackling complex molecular dynamics problems that are currently intractable for classical computers. The core idea involves leveraging the principles of quantum mechanics to model molecular systems, specifically focusing on simulating the dynamic behavior of molecules and their interactions. We propose a framework for constructing a quantum simulator utilizing quantum bits (qubits) to represent and evolve molecular states. The theoretical framework presented herein outlines the methodology for mapping molecular dynamics problems onto a quantum computational platform, highlighting the advantages and challenges associated with this approach. Specifically, we examine the impact of quantum effects, such as superposition and entanglement, on the simulation accuracy and efficiency. This work contributes to the nascent field of quantum molecular dynamics and provides a foundation for future investigations into the development of practical quantum simulation tools. The key objective is to demonstrate that quantum simulation, when properly implemented, can significantly outperform classical methods for simulating complex molecular systems, particularly those involving significant quantum effects.

Xingyu Zhang, Weijia Guo, Jinke Yu +1 more

In this work, we explore the implementation possibility of quantum simulation for quantum molecular dynamics, in particular for reaction dynamics, though several implementations have already reported through quantum-classical mixed simulations ({\it Acc. Chem. Res.} {\bf 54} (2021), 4229 and {\it J. Phys. Chem. Lett.} {\bf xx} (2026), XXXX). To analyze this aspect, we examine (1) the conjugacy relation between quantum simulator and the target molecular system, (2) the wave function correspondence in quantum algorithm and classical algorithm for multi-dimensional dynamics, (3) problems arisen from real-valued classical algorithms, and finally (4) geometric phase arisen from the separation among the degrees of freedom (DOFs). As is well known, the aforementioned first and second points play fundamental roles in quantum simulation of quantum many-body systems, and the third and fourth points are theoretical issues that might introduce problems in classical and quantum computing. In this work, we mainly focus on the third and fourth points by analysis of the first two points by reviewing previously reported quantum-classical mixed implementations of quantum simulation. We also consider gauge freedom in high-dimensional quantum molecular dynamics that has been introduced recently, and then discuss possibility of advantages and disadvantages of quantum simulation for molecular reaction dynamics.

Momoji Kubo