发表机构
Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences; School of Physical Sciences, University of Chinese Academy of Sciences; Division of Chemistry and Chemical Engineering, California Institute of Technology; PSI Center for Scientific Computing, Theory and Data, Paul Scherrer Institute（中国科学院物理研究所，北京凝聚态物理国家研究中心; 中国科学院大学物理科学学院; 加州理工学院化学与化工系; 保罗谢尔研究所科学计算、理论与数据中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究针对现有张量网络量子动力学方法的数值不稳定性问题，提出ET-CTMRG方法，提升了激发谱计算精度，在$\boldsymbol{\rm K_2Co(SeO_3)_2}$超固相的谱函数计算中与实验结果高度吻合。
AI 中文摘要
张量网络方法为研究二维量子系统的动力学谱函数开辟了有效途径，但现有无限投影纠缠对态框架内的方法仅从基态环境构造所需的重正化张量，易出现严重数值不稳定性。本研究明确了该不稳定性的来源，提出了激发定制角转移矩阵重正化群（ET-CTMRG）方法以解决该问题；通过在重正化过程中引入激发张量，该方法能构造精度显著更高的有效哈密顿矩阵，从而得到可靠且收敛性良好的激发谱。对于海森堡反铁磁体，该方法将截断误差降低数个数量级；针对三角格子XXZ磁体$\boldsymbol{\rm K_2Co(SeO_3)_2}$超固相这一复杂案例，其与非弹性中子散射测量结果实现了极佳的定量吻合。因此，ET-CTMRG为研究强关联量子系统的动力学性质提供了可靠框架。
英文摘要
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 $\mathrm{K_2Co(SeO_3)_2}$, 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.
Comments17 pages, 13 figures
