Robustness of near-thermal dynamics on digital quantum computers

Fuente: arXiv
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Main Authors: Chertkov, Eli, Chen, Yi-Hsiang, Lubasch, Michael, Hayes, David, Foss-Feig, Michael
Format: Preprint
Published: 2024
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author Chertkov, Eli
Chen, Yi-Hsiang
Lubasch, Michael
Hayes, David
Foss-Feig, Michael
author_facet Chertkov, Eli
Chen, Yi-Hsiang
Lubasch, Michael
Hayes, David
Foss-Feig, Michael
contents Understanding the impact of gate errors on quantum circuits is crucial to determining the potential applications of quantum computers, especially in the absence of large-scale error-corrected hardware. We put forward analytical arguments, corroborated by extensive numerical and experimental evidence, that Trotterized quantum circuits simulating the time-evolution of systems near thermal equilibrium are substantially more robust to both quantum gate errors and Trotter (discretization) errors than is widely assumed. In Quantinuum's trapped-ion computers, the weakly entangling gates that appear in Trotterized circuits can be implemented natively, and their error rate is smaller when they generate less entanglement; from benchmarking, we know that the error for a gate $\exp[-i (Z\otimes Z) τ]$ decreases roughly linearly with $τ$, up to a small offset at $τ= 0$. We provide extensive evidence that this scaling, together with the robustness of near-thermal dynamics to both gate and discretization errors, facilitates substantial improvements in the achievable accuracy of Trotterized dynamics on near-term quantum computers. We make heavy use of a new theoretical tool -- a statistical ensemble of random product states that approximates a thermal state, which can be efficiently prepared with low noise on quantum computers. We outline how the random product state ensemble can be used to predict, optimize, and design Hamiltonian simulation experiments on near-thermal quantum systems.
format Preprint
id arxiv_https___arxiv_org_abs_2410_10794
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Robustness of near-thermal dynamics on digital quantum computers
Chertkov, Eli
Chen, Yi-Hsiang
Lubasch, Michael
Hayes, David
Foss-Feig, Michael
Quantum Physics
Mesoscale and Nanoscale Physics
Statistical Mechanics
Strongly Correlated Electrons
Understanding the impact of gate errors on quantum circuits is crucial to determining the potential applications of quantum computers, especially in the absence of large-scale error-corrected hardware. We put forward analytical arguments, corroborated by extensive numerical and experimental evidence, that Trotterized quantum circuits simulating the time-evolution of systems near thermal equilibrium are substantially more robust to both quantum gate errors and Trotter (discretization) errors than is widely assumed. In Quantinuum's trapped-ion computers, the weakly entangling gates that appear in Trotterized circuits can be implemented natively, and their error rate is smaller when they generate less entanglement; from benchmarking, we know that the error for a gate $\exp[-i (Z\otimes Z) τ]$ decreases roughly linearly with $τ$, up to a small offset at $τ= 0$. We provide extensive evidence that this scaling, together with the robustness of near-thermal dynamics to both gate and discretization errors, facilitates substantial improvements in the achievable accuracy of Trotterized dynamics on near-term quantum computers. We make heavy use of a new theoretical tool -- a statistical ensemble of random product states that approximates a thermal state, which can be efficiently prepared with low noise on quantum computers. We outline how the random product state ensemble can be used to predict, optimize, and design Hamiltonian simulation experiments on near-thermal quantum systems.
title Robustness of near-thermal dynamics on digital quantum computers
topic Quantum Physics
Mesoscale and Nanoscale Physics
Statistical Mechanics
Strongly Correlated Electrons
url https://arxiv.org/abs/2410.10794