Optimized Tensor-Network Renormalization for Quantum Dynamics: Resolving the Spectral Function of K2Co(SeO3)2
Abstract
Tensor-network methods have opened a powerful route for the study of dynamical spectral functions in two-dimensional quantum systems. However, existing approaches within the framework of infinite projected entangled-pair states construct the required renormalization tensors solely from the ground-state environment and can suffer from severe numerical instability. We identify the origin of this instability and introduce an excitation-tailored corner-transfer-matrix renormalization-group (ET-CTMRG) method to resolve it. By incorporating excitation tensors into the renormalization procedure, the method constructs a substantially more accurate effective Hamiltonian matrix and thereby yields reliable and well-converged excitation spectra. For Heisenberg antiferromagnets, it reduces truncation errors by orders of magnitude and for the particularly complex case of the supersolid phase in the triangular-lattice XXZ magnet K2Co(SeO3)2, it achieves excellent quantitative agreement with inelastic neutron-scattering measurements. ET-CTMRG therefore provides a robust framework for investigating the dynamical properties of strongly correlated quantum systems.
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BibTeX
@misc{hu2026optimized,
title = {{Optimized Tensor-Network Renormalization for Quantum Dynamics: Resolving the Spectral Function of $\mathrmK_2Co(SeO_3)_2$}},
author = {Jiahang Hu and Runze Chi and B. Normand and Hai-Jun Liao and T. Xiang},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2608.02473},
eprint = {2608.02473},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2608.02473},
}
RIS
TY - UNPB
TI - Optimized Tensor-Network Renormalization for Quantum Dynamics: Resolving the Spectral Function of K_2Co(SeO_3)_2
AU - Jiahang Hu
AU - Runze Chi
AU - B. Normand
AU - Hai-Jun Liao
AU - T. Xiang
PY - 2026
DA - 2026/09/13
PB - arXiv
DO - 10.48550/arxiv.2608.02473
UR - https://arxiv.org/abs/2608.02473
AB - Tensor-network methods have opened a powerful route for the study of dynamical spectral functions in two-dimensional quantum systems. However, existing approaches within the framework of infinite projected entangled-pair states construct the required renormalization tensors solely from the ground-state environment and can suffer from severe numerical instability. We identify the origin of this instability and introduce an excitation-tailored corner-transfer-matrix renormalization-group (ET-CTMRG) method to resolve it. By incorporating excitation tensors into the renormalization procedure, the method constructs a substantially more accurate effective Hamiltonian matrix and thereby yields reliable and well-converged excitation spectra. For Heisenberg antiferromagnets, it reduces truncation errors by orders of magnitude and for the particularly complex case of the supersolid phase in the triangular-lattice XXZ magnet K_2Co(SeO_3)_2, it achieves excellent quantitative agreement with inelastic neutron-scattering measurements. ET-CTMRG therefore provides a robust framework for investigating the dynamical properties of strongly correlated quantum systems.
ER -