469 citations · 2.7k across the 72 of their papers we have counts for
25 papers · 1 filter
Angular-time evolution and edge-spin dynamics in the Haldane phase of the S=1 bilinear-biquadratic chain
Takuma Kaise, Kouichi Okunishi
We investigate the angular-time evolution -- a parameter-time evolution generated by the entanglement Hamiltonian -- for the bipartitioned ground state of the S=1 bilinear-biquadra…
Translational Symmetry Broken Magnetization Plateau of the Anisotropic Spin Ladder with Ferromagnetic Rung Interaction
Tôru Sakai, Koki Doi, Kiyomi Okamoto +5
The magnetization process of the anisotropic spin ladder with the ferromagnetic rung interaction is investigated using the numerical diagonalization of finite-size clusters…
Translational symmetry broken magnetization plateau of the S=1 antiferromagnetic Heisenberg chain with competing anisotropies
Tôru Sakai, Kiyomi Okamoto, Kouichi Okunishi +4
We investigate the S=1 antiferromagnetic quantum spin chain with the exchange and single-ion anisotropies in a magnetic field, using the numerical exact diagonalization of finite-s…
Duality, Criticality, Anomaly, and Topology in Quantum Spin-1 Chains
Hong Yang, Linhao Li, Kouichi Okunishi +1
In quantum spin-1 chains, there is a nonlocal unitary transformation known as the Kennedy-Tasaki transformation , which defines a duality between the Haldane phase a…
Entanglement-based tensor-network strong-disorder renormalization group
Kouichi Seki, Toshiya Hikihara, Kouichi Okunishi
We propose an entanglement-based algorithm of the tensor-network strong-disorder renormalization group (tSDRG) method for quantum spin systems with quenched randomness. In contrast…
Tensor-network strong-disorder renormalization groups for random quantum spin systems in two dimensions
Kouichi Seki, Toshiya Hikihara, Kouichi Okunishi
Novel randomness-induced disordered ground states in two-dimensional (2D) quantum spin systems have been attracting much interest. For quantitative analysis of such random quantum…