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Bibliographic Details
Main Authors: Santos, R. F. dos, Kokkelmans, S. J. J. M. F.
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2512.20357
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author Santos, R. F. dos
Kokkelmans, S. J. J. M. F.
author_facet Santos, R. F. dos
Kokkelmans, S. J. J. M. F.
contents The evolution of a quantum system under time-dependent driving exhibits phenomena that are absent in its stationary counterpart. However, the high dimensionality and non-commutative nature of quantum dynamics make this a challenging problem. The Magnus expansion provides an analytic framework to approximate the effective dynamics on short time-scales, but computing high-order terms with existing methods is computationally expensive. We introduce a scalable approach that reduces the computational effort to depend only on the degrees of freedom defining the time-dependent control function. We focus specifically on Hamiltonians consisting of a constant drift term and a controllable term. Our method provides a polynomial expression for the Magnus expansion which can be evaluated several orders of magnitude faster than previous techniques, enabling broad applications in the realms of quantum simulation and quantum optimal control. We showcase an application of the method by designing control pulses for the 5-qubit phase gate on a neutral-atom platform utilizing Rydberg atoms.
format Preprint
id arxiv_https___arxiv_org_abs_2512_20357
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Lie algebra-assisted quantum simulation and quantum optimal control via high-order Magnus expansions
Santos, R. F. dos
Kokkelmans, S. J. J. M. F.
Quantum Physics
The evolution of a quantum system under time-dependent driving exhibits phenomena that are absent in its stationary counterpart. However, the high dimensionality and non-commutative nature of quantum dynamics make this a challenging problem. The Magnus expansion provides an analytic framework to approximate the effective dynamics on short time-scales, but computing high-order terms with existing methods is computationally expensive. We introduce a scalable approach that reduces the computational effort to depend only on the degrees of freedom defining the time-dependent control function. We focus specifically on Hamiltonians consisting of a constant drift term and a controllable term. Our method provides a polynomial expression for the Magnus expansion which can be evaluated several orders of magnitude faster than previous techniques, enabling broad applications in the realms of quantum simulation and quantum optimal control. We showcase an application of the method by designing control pulses for the 5-qubit phase gate on a neutral-atom platform utilizing Rydberg atoms.
title Lie algebra-assisted quantum simulation and quantum optimal control via high-order Magnus expansions
topic Quantum Physics
url https://arxiv.org/abs/2512.20357