Time-Dependent Hamiltonian Simulation in the Low-Energy Subspace

Fuente: arXiv
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Hauptverfasser: Zhou, Shuo, Pan, Zhaokai, Gong, Weiyuan, Li, Tongyang
Format: Preprint
Veröffentlicht: 2026
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author Zhou, Shuo
Pan, Zhaokai
Gong, Weiyuan
Li, Tongyang
author_facet Zhou, Shuo
Pan, Zhaokai
Gong, Weiyuan
Li, Tongyang
contents Hamiltonian simulations are key subroutines in adiabatic quantum computation, quantum control, and quantum many-body physics, where quantum dynamics often happen in the low-energy sector. In contrast to time-independent Hamiltonian simulations, a comprehensive understanding of quantum simulation algorithms for time-dependent Hamiltonians under the low-energy assumption remains limited hitherto. In this paper, we investigate how much we can improve upon the standard performance guarantee assuming the initial state is supported on a low-energy subspace. In particular, we compute the Trotter number of digital quantum simulation based on product formulas for time-dependent spin Hamiltonians under the low-energy assumption that the initial state is supported on a small number of low-energy eigenstates, and show improvements over the standard cost for simulating full unitary simulations. Technically, we derive the low-energy simulation error with commutator scaling for product formulas by leveraging adiabatic perturbation theory to analyze the time-variant energy spectrum of the underlying Hamiltonian. We further discuss the applications to simulations of non-equilibrium quantum many-body dynamics and adiabatic state preparation. Finally, we prove a lower bound of query complexity for generic time-dependent Hamiltonian simulations.
format Preprint
id arxiv_https___arxiv_org_abs_2601_01550
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Time-Dependent Hamiltonian Simulation in the Low-Energy Subspace
Zhou, Shuo
Pan, Zhaokai
Gong, Weiyuan
Li, Tongyang
Quantum Physics
Data Structures and Algorithms
Hamiltonian simulations are key subroutines in adiabatic quantum computation, quantum control, and quantum many-body physics, where quantum dynamics often happen in the low-energy sector. In contrast to time-independent Hamiltonian simulations, a comprehensive understanding of quantum simulation algorithms for time-dependent Hamiltonians under the low-energy assumption remains limited hitherto. In this paper, we investigate how much we can improve upon the standard performance guarantee assuming the initial state is supported on a low-energy subspace. In particular, we compute the Trotter number of digital quantum simulation based on product formulas for time-dependent spin Hamiltonians under the low-energy assumption that the initial state is supported on a small number of low-energy eigenstates, and show improvements over the standard cost for simulating full unitary simulations. Technically, we derive the low-energy simulation error with commutator scaling for product formulas by leveraging adiabatic perturbation theory to analyze the time-variant energy spectrum of the underlying Hamiltonian. We further discuss the applications to simulations of non-equilibrium quantum many-body dynamics and adiabatic state preparation. Finally, we prove a lower bound of query complexity for generic time-dependent Hamiltonian simulations.
title Time-Dependent Hamiltonian Simulation in the Low-Energy Subspace
topic Quantum Physics
Data Structures and Algorithms
url https://arxiv.org/abs/2601.01550