Continuous Hamiltonian dynamics on digital quantum computers without discretization error

Fuente: arXiv
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Main Authors: Granet, Etienne, Dreyer, Henrik
Format: Preprint
Published: 2023
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author Granet, Etienne
Dreyer, Henrik
author_facet Granet, Etienne
Dreyer, Henrik
contents We introduce an algorithm to compute Hamiltonian dynamics on digital quantum computers that requires only a finite circuit depth to reach an arbitrary precision, i.e. achieves zero discretization error with finite depth. This finite number of gates comes at the cost of an attenuation of the measured expectation value by a known amplitude, requiring more shots per circuit. The gate count for simulation up to time $t$ is $O(t^2μ^2)$ with $μ$ the $1$-norm of the Hamiltonian, without dependence on the precision desired on the result, providing a significant improvement over previous algorithms. The only dependence in the norm makes it particularly adapted to non-sparse Hamiltonians. The algorithm generalizes to time-dependent Hamiltonians, appearing for example in adiabatic state preparation. These properties make it particularly suitable for present-day relatively noisy hardware that supports only circuits with moderate depth.
format Preprint
id arxiv_https___arxiv_org_abs_2308_03694
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Continuous Hamiltonian dynamics on digital quantum computers without discretization error
Granet, Etienne
Dreyer, Henrik
Quantum Physics
We introduce an algorithm to compute Hamiltonian dynamics on digital quantum computers that requires only a finite circuit depth to reach an arbitrary precision, i.e. achieves zero discretization error with finite depth. This finite number of gates comes at the cost of an attenuation of the measured expectation value by a known amplitude, requiring more shots per circuit. The gate count for simulation up to time $t$ is $O(t^2μ^2)$ with $μ$ the $1$-norm of the Hamiltonian, without dependence on the precision desired on the result, providing a significant improvement over previous algorithms. The only dependence in the norm makes it particularly adapted to non-sparse Hamiltonians. The algorithm generalizes to time-dependent Hamiltonians, appearing for example in adiabatic state preparation. These properties make it particularly suitable for present-day relatively noisy hardware that supports only circuits with moderate depth.
title Continuous Hamiltonian dynamics on digital quantum computers without discretization error
topic Quantum Physics
url https://arxiv.org/abs/2308.03694