Fast-forwarding quantum algorithms for linear dissipative differential equations

Fuente: arXiv
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Autori principali: An, Dong, Onwunta, Akwum, Yang, Gengzhi
Natura: Preprint
Pubblicazione: 2024
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author An, Dong
Onwunta, Akwum
Yang, Gengzhi
author_facet An, Dong
Onwunta, Akwum
Yang, Gengzhi
contents We establish improved complexity estimates of quantum algorithms for linear dissipative ordinary differential equations (ODEs) and show that the time dependence can be fast-forwarded to be sub-linear. Specifically, we show that a quantum algorithm based on truncated Dyson series can prepare history states of dissipative ODEs up to time $T$ with cost $\widetilde{\mathcal{O}}(\log(T) (\log(1/ε))^2 )$, which is an exponential speedup over the best previous result. For final state preparation at time $T$, we show that its complexity is $\widetilde{\mathcal{O}}(\sqrt{T} (\log(1/ε))^2 )$, achieving a polynomial speedup in $T$. We also analyze the complexity of simpler lower-order quantum algorithms, such as the forward Euler method and the trapezoidal rule, and find that even lower-order methods can still achieve $\widetilde{\mathcal{O}}(\sqrt{T})$ cost with respect to time $T$ for preparing final states of dissipative ODEs. As applications, we show that quantum algorithms can simulate dissipative non-Hermitian quantum dynamics and heat processes with fast-forwarded complexity sub-linear in time.
format Preprint
id arxiv_https___arxiv_org_abs_2410_13189
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Fast-forwarding quantum algorithms for linear dissipative differential equations
An, Dong
Onwunta, Akwum
Yang, Gengzhi
Quantum Physics
Numerical Analysis
We establish improved complexity estimates of quantum algorithms for linear dissipative ordinary differential equations (ODEs) and show that the time dependence can be fast-forwarded to be sub-linear. Specifically, we show that a quantum algorithm based on truncated Dyson series can prepare history states of dissipative ODEs up to time $T$ with cost $\widetilde{\mathcal{O}}(\log(T) (\log(1/ε))^2 )$, which is an exponential speedup over the best previous result. For final state preparation at time $T$, we show that its complexity is $\widetilde{\mathcal{O}}(\sqrt{T} (\log(1/ε))^2 )$, achieving a polynomial speedup in $T$. We also analyze the complexity of simpler lower-order quantum algorithms, such as the forward Euler method and the trapezoidal rule, and find that even lower-order methods can still achieve $\widetilde{\mathcal{O}}(\sqrt{T})$ cost with respect to time $T$ for preparing final states of dissipative ODEs. As applications, we show that quantum algorithms can simulate dissipative non-Hermitian quantum dynamics and heat processes with fast-forwarded complexity sub-linear in time.
title Fast-forwarding quantum algorithms for linear dissipative differential equations
topic Quantum Physics
Numerical Analysis
url https://arxiv.org/abs/2410.13189