Saved in:
Bibliographic Details
Main Authors: Vargas-Calderón, Vladimir, Vinck-Posada, Herbert, González, Fabio A.
Format: Preprint
Published: 2022
Subjects:
Online Access:https://arxiv.org/abs/2206.09241
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866913403758444544
author Vargas-Calderón, Vladimir
Vinck-Posada, Herbert
González, Fabio A.
author_facet Vargas-Calderón, Vladimir
Vinck-Posada, Herbert
González, Fabio A.
contents We consider the Feynman-Kitaev formalism applied to a spin chain described by the transverse field Ising model. This formalism consists of building a Hamiltonian whose ground state encodes the time evolution of the spin chain at discrete time steps. To find this ground state, variational wave functions parameterised by artificial neural networks -- also known as neural quantum states (NQSs) -- are used. Our work focuses on assessing, in the context of the Feynman-Kitaev formalism, two properties of NQSs: expressivity (the possibility that variational parameters can be set to values such that the NQS is faithful to the true ground state of the system) and trainability (the process of reaching said values). We find that the considered NQSs are capable of accurately approximating the true ground state of the system, i.e., they are expressive enough ansätze. However, extensive hyperparameter tuning experiments show that, empirically, reaching the set of values for the variational parameters that correctly describe the ground state becomes ever more difficult as the number of time steps increase because the true ground state becomes more entangled, and the probability distribution starts to spread across the Hilbert space canonical basis.
format Preprint
id arxiv_https___arxiv_org_abs_2206_09241
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle An Empirical Study of Quantum Dynamics as a Ground State Problem with Neural Quantum States
Vargas-Calderón, Vladimir
Vinck-Posada, Herbert
González, Fabio A.
Quantum Physics
Machine Learning
We consider the Feynman-Kitaev formalism applied to a spin chain described by the transverse field Ising model. This formalism consists of building a Hamiltonian whose ground state encodes the time evolution of the spin chain at discrete time steps. To find this ground state, variational wave functions parameterised by artificial neural networks -- also known as neural quantum states (NQSs) -- are used. Our work focuses on assessing, in the context of the Feynman-Kitaev formalism, two properties of NQSs: expressivity (the possibility that variational parameters can be set to values such that the NQS is faithful to the true ground state of the system) and trainability (the process of reaching said values). We find that the considered NQSs are capable of accurately approximating the true ground state of the system, i.e., they are expressive enough ansätze. However, extensive hyperparameter tuning experiments show that, empirically, reaching the set of values for the variational parameters that correctly describe the ground state becomes ever more difficult as the number of time steps increase because the true ground state becomes more entangled, and the probability distribution starts to spread across the Hilbert space canonical basis.
title An Empirical Study of Quantum Dynamics as a Ground State Problem with Neural Quantum States
topic Quantum Physics
Machine Learning
url https://arxiv.org/abs/2206.09241