Quantum nuclear dynamics on a distributed set of ion-trap quantum computing systems

TL;DR

This paper demonstrates the use of a distributed ion-trap quantum computer to simulate quantum nuclear dynamics of a molecule, achieving chemical accuracy and pioneering parallel quantum computation for chemical problems.

Contribution

It introduces the first application of distributed quantum computing to chemical dynamics, combining ion-trap systems with tensor network formalism for molecular simulations.

Findings

Quantum wavepacket dynamics emulated with good agreement to classical results

Vibrational energies match classical simulations within a fraction of a kcal/mol

First demonstration of parallel quantum computation on distributed ion-trap systems

Abstract

Quantum nuclear dynamics with wavepacket time-evolution is classically intractable and viewed as a promising avenue for quantum information processing. Here, we use an IonQ 11-qubit trapped-ion quantum computer, Harmony, to study the quantum wavepacket dynamics of a shared-proton within a short-strong hydrogen-bonded system. We also provide the first application of distributed quantum computing for chemical dynamics problems, where the distributed set of quantum processes is constructed using a tensor network formalism. For a range of initial states, we experimentally drive the ion-trap system to emulate the quantum nuclear wavepacket as it evolves along the potential surface generated from electronic structure. Following the experimental creation of the nuclear wavepacket, we extract measurement observables such as its time-dependent spatial projection and its characteristic vibrational frequencies to good agreement with classical results. Vibrational eigenenergies obtained from quantum computational are in agreement with those obtained from classical simulations to within a fraction of a kcal/mol, thus suggesting chemical accuracy. Our approach opens a new paradigm for studying the quantum chemical dynamics and vibrational spectra of molecules and also provides the first demonstration for parallel quantum computation on a distributed set of ion-trap quantum computers.