104 citations · 794 across the 40 of their papers we have counts for
21 papers · 1 filter
Gaussian fixed lines of XXZ chain with next-nearest neighbor interaction and loop algebra
Daiki Yomatsu, Kiyohide Nomura
Spin systems are important to understand various physical properties in quantum many-body systems. We numerically study the Gaussian fixed lines (GFLs) of the XXZ chain wit…
Critical phenomena around the SU(3) symmetric tri-critical point of a spin-1 chain
Tohru Mashiko, Kiyohide Nomura
We investigate critical phenomena of a spin-1 chain in the vicinity of the SU(3) symmetric critical point, which we already specified in the previous study. We numerically diagonal…
Phase transition of an SU(3) symmetric spin-1 chain
Tohru Mashiko, Kiyohide Nomura
We investigate a phase transition in an SU(3) symmetric spin-1 chain. We identify the universality class of the critical trimer liquid phase, as well as the phase boundary between…
A new method to calculate a 2d ising universality transition point : application near the ashkin-teller multicritical point
S. Moriya, K. Nomura
We propose a new method to numerically calculate transition points that belongs to 2D Ising universality class for quantum spin models. Generally, near the multicritical point, in…
Universality Class around the SU(3) Symmetric Point of the Dimer-Trimer Spin-1 Chain
Tohru Mashiko, Shunji Moriya, Kiyohide Nomura
We study critical phenomena of the SU(3) symmetric spin-1 chains when adding the SU(3) asymmetric term. To investigate such system, we numerically diagonalize the Dimer-Trimer (DT)…
Method to Observe Anomaly of Magnetic Susceptibility for Quantum Spin Systems
Nobutaka Aiba, Kiyohide Nomura
We propose a new method for studying the anomaly of magnetic susceptibility that indicates a phase transition for quantum spin systems. In addition, we introduce the fourth der…
Extension of the Lieb-Schultz-Mattis and Kolb theorem
Kiyohide Nomura
The theorem of Lieb, Schultz and Mattis (LSM), which states that the S=1/2 XXZ spin chain has gapless or degenerate ground states, can be applied to broader models. Independently,…
Discrete symmetries and Lieb-Schultz-Mattis theorem
Takaichi Isoyama, Kiyohide Nomura
In this study, we consider one-dimension (1D) quantum spin systems with the translation and discrete symmetries (spin reversal, space inversion and time reversal symmetries). By co…
Extension of the Lieb-Schultz-Mattis theorem
Kiyohide Nomura, Junpei Morishige, Takaichi Isoyama
Lieb, Schultz and Mattis (LSM) studied the S=1/2 XXZ spin chain. Theorems of LSM's paper can be applied to broader models. In the original LSM theorem it was assumed the nonfrustra…
How to distinguish the Haldane/Large-D state and the intermediate-D state in an S=2 quantum spin chain with the XXZ and on-site anisotropies
Kiyomi Okamoto, Takashi Tonegawa, Hiroki Nakano +3
We numerically investigate the ground-state phase diagram of an S=2 quantum spin chain with the and on-site anisotropies described by ${\mathcal H}=\sum_j (S_j^x S_{j+1}^x+S_…
Critical intermediate phase and phase transitions in a triangular-lattice three-spin interaction model: Level-spectroscopy approach
Hiromi Otsuka, Kiyohide Nomura
We investigate infinite-order phase transitions like the Berezinskii-Kosterlitz-Thouless transition observed in a triangular-lattice three-spin interaction model. Based on a field…
Global phase diagram and six-state clock universality behavior in the triangular antiferromagnetic Ising model with anisotropic next-nearest-neighbor coupling: Level-spectroscopy approach
Hiromi Otsuka, Yutaka Okabe, Kiyohide Nomura
We investigate the triangular-lattice antiferromagnetic Ising model with a spatially anisotropic next-nearest-neighbor ferromagnetic coupling, which was first discussed by Kitatani…
Berezinskii-Kosterlitz-Thouless transitions in the six-state clock model
Haruhiko Matsuo, Kiyohide Nomura
Classical 2D clock model is known to have a critical phase with Berezinskii-Kosterlitz-Thouless(BKT) transitions. These transitions have logarithmic corrections which make numerica…
Level spectroscopy of the square-lattice three-state Potts model with a ferromagnetic next-nearest-neighbor coupling
Hiromi Otsuka, Koutaro Mori, Yutaka Okabe +1
We study the square-lattice three-state Potts model with the ferromagnetic next-nearest-neighbor coupling at finite temperature. Using the level-spectroscopy method, we numerically…
Staggered dimer order in S=1/2 quantum spin ladder system with four spin exchange
Keigo Hijii, Shaojin Qin, Kiyohide Nomura
We study the S=1/2 quantum spin ladder system with the four-spin exchange, using density matrix renormalization group method and an exact diagonalization method. Recently, the phas…
Universality class of S=1/2 quantum spin ladder system with the four spin exchange
Keigo Hijii, Kiyohide Nomura
We study s=1/2 Heisenberg spin ladder with the four spin exchange. Combining numerical results with the conformal field theory(CFT), we find a phase transition with central charge…
Phase diagram of S=1/2 XXZ chain with NNN interaction
Shunsaku Hirata, Kiyohide Nomura
We study the ground state properties of one-dimensional XXZ model with next-nearest neighbor coupling alpha and anisotropy Delta. We find the direct transition between the ferromag…
Bifurcation at the c=3/2 Takhtajan-Babujian point to the c=1 critical lines
Atsuhiro Kitazawa, Kiyohide Nomura
We study the S=1 quantum spin chains with bilinear, biquadratic, plus bond alternation in the vicinity of the S=1 Takhtajan-Babujian model. Transition line between the Haldane and…
symmetry of the BKT transition and twisted boundary conditio n
Kiyohide Nomura, Atsuhiro Kitazawa
Berezinskii-Kosterlitz-Thouless (BKT) transition, the transition of the 2D sine-Gordon model, plays an important role in the low dimensional physics. We relate the operator content…
Berezinskii-Kosterlitz-Thouless Transition of Spin-1 XXZ Chains in a Staggered Magnetic Field
Masayoshi Tsukano, Kiyohide Nomura
Phase diagram of S=1 XXZ chain in a staggered magnetic field is obtained numerically. The Berezinskii-Kosterlitz-Thouless transition between the XY and the antiferromagnetic phases…
Phase Diagrams of S=3/2, 2 XXZ Spin Chains with Bond-Alternation
Atsuhiro Kitazawa, Kiyohide Nomura
We study the phase diagram of S=3/2 and S=2 bond-alternating spin chains numerically. In previous papers, the phase diagram of S=1 XXZ spin chain with bond-alternation was shown to…