Vibrational ADAPT-VQE: Critical points leads to problematic convergence

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Majland, Marco, Ettenhuber, Patrick, Zinner, Nikolaj Thomas, Christiansen, Ove
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866910960174759936
author Majland, Marco
Ettenhuber, Patrick
Zinner, Nikolaj Thomas
Christiansen, Ove
author_facet Majland, Marco
Ettenhuber, Patrick
Zinner, Nikolaj Thomas
Christiansen, Ove
contents Quantum chemistry is one of the most promising applications for which quantum computing is expected to have significant impact. Despite considerable research in the field of electronic structure, calculating the vibrational properties of molecules on quantum computers remain a relatively unexplored field. In this work, we develop a vibrational ADAPT-VQE (vADAPT-VQE) formalism based on an infinite product representation (IPR) of anti-Hermitian excitation operators of the Full Vibrational Configuration Interaction (FVCI) wavefunction which allows for preparing eigenstates of vibrational Hamiltonians on quantum computers. In order to establish the vADAPT- VQE algorithm using the IPR, we study the exactness of disentangled Unitary Vibrational Coupled Cluster (dUVCC) theory and show that dUVCC can formally represent the FVCI wavefunction in an infinite expansion. To investigate the performance of the vADAPT-VQE algorithm, we numerically study whether the vADAPT-VQE algorithm generates a sequence of operators which may represent the FVCI wavefunction. Our numerical results indicate frequent appearance of critical points in the wavefunction preparation using vADAPT-VQE. These results imply that one may encounter diminishing usefulness when preparing vibrational wavefunctions on quantum computers using vADAPT-VQE and that additional studies are required to find methods that can circumvent this behavior.
format Preprint
id arxiv_https___arxiv_org_abs_2404_06770
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Vibrational ADAPT-VQE: Critical points leads to problematic convergence
Majland, Marco
Ettenhuber, Patrick
Zinner, Nikolaj Thomas
Christiansen, Ove
Quantum Physics
Computational Physics
Quantum chemistry is one of the most promising applications for which quantum computing is expected to have significant impact. Despite considerable research in the field of electronic structure, calculating the vibrational properties of molecules on quantum computers remain a relatively unexplored field. In this work, we develop a vibrational ADAPT-VQE (vADAPT-VQE) formalism based on an infinite product representation (IPR) of anti-Hermitian excitation operators of the Full Vibrational Configuration Interaction (FVCI) wavefunction which allows for preparing eigenstates of vibrational Hamiltonians on quantum computers. In order to establish the vADAPT- VQE algorithm using the IPR, we study the exactness of disentangled Unitary Vibrational Coupled Cluster (dUVCC) theory and show that dUVCC can formally represent the FVCI wavefunction in an infinite expansion. To investigate the performance of the vADAPT-VQE algorithm, we numerically study whether the vADAPT-VQE algorithm generates a sequence of operators which may represent the FVCI wavefunction. Our numerical results indicate frequent appearance of critical points in the wavefunction preparation using vADAPT-VQE. These results imply that one may encounter diminishing usefulness when preparing vibrational wavefunctions on quantum computers using vADAPT-VQE and that additional studies are required to find methods that can circumvent this behavior.
title Vibrational ADAPT-VQE: Critical points leads to problematic convergence
topic Quantum Physics
Computational Physics
url https://arxiv.org/abs/2404.06770