6 papers
Correlation functions at the topological quantum phase transition in the S=1 XXZ chain with single-ion anisotropy
Toshiya Hikihara, Akira Furusaki
We study the one-dimensional S=1 XXZ spin model with single-ion anisotropy. It is known that at the transition points between the Haldane and large-D phases, the model exhibits a q…
Tree-Graph Based Construction of Quantum Spin Models with Exact Ground State
Toshiya Hikihara
We propose a protocol to generate an antiferromagnetic S=1/2 Heisenberg model with the exact ground state based on a tree graph. The generated model has a correspondence with a tre…
Site-Order Optimization in the Density Matrix Renormalization Group via Multi-Site Rearrangement
Ryo Watanabe, Toshiya Hikihara, Hiroshi Ueda
In the approaches based on matrix-product states (MPSs), such as the density-matrix renormalization group (DMRG) method, the ordering of the sites crucially affects the computation…
Visualization of Entanglement Geometry by Structural Optimization of Tree Tensor Network
Toshiya Hikihara, Hiroshi Ueda, Kouichi Okunishi +2
In tensor-network analysis of quantum many-body systems, it is of crucial importance to employ a tensor network with a spatial structure suitable for representing the state of inte…
Improving accuracy of tree-tensor network approach by optimization of network structure
Toshiya Hikihara, Hiroshi Ueda, Kouichi Okunishi +2
Numerical methods based on tensor networks have been extensively explored in the research of quantum many-body systems in recent years. It has been recognized that the ability of t…
TTNOpt: Tree tensor network package for high-rank tensor compression
Ryo Watanabe, Hidetaka Manabe, Toshiya Hikihara +1
We have developed TTNOpt, a software package that utilizes tree tensor networks (TTNs) for quantum spin systems and high-dimensional data analysis. TTNOpt provides efficient and po…