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Autori principali: Morrone, Daniele, Talarico, N. Walter, Cattaneo, Marco, Rossi, Matteo A. C.
Natura: Preprint
Pubblicazione: 2024
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Accesso online:https://arxiv.org/abs/2406.04475
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author Morrone, Daniele
Talarico, N. Walter
Cattaneo, Marco
Rossi, Matteo A. C.
author_facet Morrone, Daniele
Talarico, N. Walter
Cattaneo, Marco
Rossi, Matteo A. C.
contents By leveraging the Variational Quantum Eigensolver (VQE), the ``quantum equation of motion" (qEOM) method established itself as a promising tool for quantum chemistry on near term quantum computers, and has been used extensively to estimate molecular excited states. Here, we explore a novel application of this method, employing it to compute thermal averages of quantum systems, specifically molecules like ethylene and butadiene. A drawback of qEOM is that it requires measuring the expectation values of a large number of observables on the ground state of the system, and the number of necessary measurements can become a bottleneck of the method. In this work we focus on measurements through informationally complete positive operator-valued measures (IC-POVMs) to achieve a reduction in the measurements overheads. We show with numerical simulations that the qEOM combined with IC-POVM measurements ensures a satisfactory accuracy in the reconstruction of the thermal state with a reasonable number of shots.
format Preprint
id arxiv_https___arxiv_org_abs_2406_04475
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Estimating molecular thermal averages with the quantum equation of motion and informationally complete measurements
Morrone, Daniele
Talarico, N. Walter
Cattaneo, Marco
Rossi, Matteo A. C.
Quantum Physics
By leveraging the Variational Quantum Eigensolver (VQE), the ``quantum equation of motion" (qEOM) method established itself as a promising tool for quantum chemistry on near term quantum computers, and has been used extensively to estimate molecular excited states. Here, we explore a novel application of this method, employing it to compute thermal averages of quantum systems, specifically molecules like ethylene and butadiene. A drawback of qEOM is that it requires measuring the expectation values of a large number of observables on the ground state of the system, and the number of necessary measurements can become a bottleneck of the method. In this work we focus on measurements through informationally complete positive operator-valued measures (IC-POVMs) to achieve a reduction in the measurements overheads. We show with numerical simulations that the qEOM combined with IC-POVM measurements ensures a satisfactory accuracy in the reconstruction of the thermal state with a reasonable number of shots.
title Estimating molecular thermal averages with the quantum equation of motion and informationally complete measurements
topic Quantum Physics
url https://arxiv.org/abs/2406.04475