Quantum Computation of Hydrogen Bond Dynamics and Vibrational Spectra

TL;DR

This paper presents a quantum computing framework for simulating hydrogen bond dynamics and vibrational spectra, demonstrating experimental emulation with high accuracy on an ion-trap quantum computer.

Contribution

It introduces a novel quantum logic approach for modeling hydrogen bonds and chemical dynamics, validated through a proof-of-principle experiment on a quantum computer.

Findings

Successfully emulated hydrogen bond wavepacket dynamics

Achieved spectroscopic accuracy of 3.3 cm$^{-1}$ in vibrational frequencies

Demonstrated high-fidelity quantum simulation of chemical systems

Abstract

Calculating the observable properties of chemical systems is often classically intractable and is widely viewed as a promising application of quantum information processing. Yet one of the most common and important chemical systems in nature - the hydrogen bond - has remained a challenge to study using quantum hardware on account of its anharmonic potential energy landscape. Here, we introduce a framework for solving hydrogen-bond systems and more generic chemical dynamics problems using quantum logic. We experimentally demonstrate a proof-of-principle instance of our method using the QSCOUT ion-trap quantum computer, in which we experimentally drive the ion-trap system to emulate the quantum wavepacket of the shared-proton within a hydrogen bond. Following the experimental creation of the shared-proton wavepacket, we then extract measurement observables such as its time-dependent spatial projection and its characteristic vibrational frequencies to spectroscopic accuracy (3.3 cm$^{-1}$ wavenumbers, corresponding to > 99.9% fidelity). Our approach introduces a new paradigm for studying the quantum chemical dynamics and vibrational spectra of molecules, and when combined with existing algorithms for electronic structure, opens the possibility to describe the complete behavior of complex molecular systems with unprecedented accuracy.