Quantum Simulation of Molecular Collisions in the Time-Dependent Formulation

TL;DR

This paper explores the potential of time-dependent quantum simulation methods to efficiently model molecular collisions, demonstrating feasibility up to certain system sizes without error correction.

Contribution

It introduces a time-dependent formulation for quantum simulations of molecular collisions, reducing system dimensionality and enabling prethreshold simulations for specific system sizes.

Findings

Prethreshold quantum simulation feasible up to Hilbert space dimension 8

Time-dependent formulation reduces system dimensionality

Error correction needed for larger systems

Abstract

Quantum particle simulations have largely been based on time-independent, split-operator schemes in which kinetic and potential operators are interwoven to provide accurate approximations to system dynamics. These simulations can be very expensive in terms of the number of gates required, although individual cases, such as tunneling, have been found where prethreshold simulations are possible. By prethreshold, we mean a quantum computation or simulation with an existing architecture and not requiring error correction. In the case of molecular collisions, switching to a time-dependent formulation can reduce the system dimensionality significantly and provide an opportunity for pre-threshold simulation. Here, we study the efficiency of gate-based quantum simulation of a set of molecular collisions of increasing complexity. We show that prethreshold quantum simulation of such systems is feasible up to Hilbert space dimension 8, but beyond that error correction would be required.