Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Science Reports of the Research Institutes, Tohoku University, Series A: Physics, Chemistry, and Metallurgy

Haldane to Dimer Phase Transition in the Spin-1 Haldane System with Bond-Alternating Nearest-Neighbor and Uniform Next-Nearest-Neighbor Exchange Interactions

Takashi Tonegawa, Makoto Kaburagi, Takeshi Nakao

Published Mar 20, 1995• 0 citations
Publisher
DOI
10.50974/00043618

Related papers

Transition from Haldane Phase to Spin Liquid and Incommensurate Correlation in Spin-1/2 Heisenberg Chains

Shinji Watanabe, Hisatoshi Yokoyama

The bulk properties and impurity effect in the one-dimensional S=1/2 Heisenberg model with dimerization and next-nearest-neighbor exchange are studied by the density matrix renormalization group (DMRG) and exact diagonalization methods. This model widely covers the S=1 Heisenberg model, two-leg ladders, bond-alternating chains and the S=1/2 Heisenberg model. Almost the whole parameter space belongs to the Haldane phase. In the non-dimerizing limit a transition to a kind of spin liquid takes place, characterized by the delocalized spin polarization. This transition causes the distinct impurity effects between a spin-Peierls compound CuGeO_{3} and the Haldane systems. Experimental aspects of a bond-alternating compound CuNb_{2}O_{6} are also discussed. Furthermore, the incommensurate correlation arising in this model is extensively studied, and a phase diagram is constructed.

arXiv:cond-mat/9902311•Journal of the Physical Society of Japan•Jun 15, 1999•40 citations

Effect of second-neighbor interactions on the ground-state phase diagram of the spin-1 Haldane system

Takashi Tonegawa, Shigeo Suzuki, Makoto Kaburagi

Journal of Magnetism and Magnetic Materials•Feb 1, 1995•7 citations

Crossover Between the Haldane Gap Phase and the Dimer Phase in the Spin 1/2 Alternating Heisenberg Chain

Kazuo Hida

Springer proceedings in physics•Jan 1, 1992•2 citations

Measurement-Only Dynamical Phase Transitions in Spin-1 Chains

Kemal Aziz, Haining Pan, J. H. Pixley

We study measurement-only dynamics in an interacting spin-1 chain, using forced, normalized local projections rather than Born-rule-sampled measurement outcomes. Starting from the nearest-neighbor (NN) Affleck-Kennedy-Lieb-Tasaki (AKLT) Haldane symmetry-protected topological state, we show that competing local projectors drive this order toward three distinct dynamical phases: a featureless topologically trivial product state, an explicitly dimerized valence-bond-solid state, and a topologically trivial next-nearest-neighbor (NNN) AKLT state consisting of two interwoven Haldane chains. Using matrix product state and exact statevector simulations, we identify continuous transitions among these phases and characterize them using nonlocal string order parameters, local dimer order, and entanglement scaling. For the NN-NNN AKLT model, finite-size signatures are consistent with an intervening extended critical regime rather than a single direct transition. These results extend studies of monitored topology to a bosonic SPT and show that local projections can control both topological and valence-bond-solid order.

quant-pharXiv:2609.26941•Sep 24, 2026•0 citations

Elementary excitations and thermodynamics of zig-zag spin ladders with alternating nearest-neighbor exchange interactions

Andrei A. Zvyagin, Vladyslav O. Cheranovskii

A one-dimensional spin-1∕2 model in which the alternation of the exchange interactions between neighboring spins is accompanied by the next-nearest-neighbor (NNN) spin exchange (zig-zag spin ladder with alternation) is studied. The thermodynamic characteristics of the model quantum spin chain are obtained in the mean-field-like approximation. Depending on the strength of the NNN interactions, the model manifests either the spin-gapped behavior of low-lying excitations at low magnetic fields, or ferrimagnetic ordering in the ground state with gapless low-lying excitations. The system undergoes second-order or first-order quantum phase transitions, governed by the external magnetic field, NNN coupling strength, and the degree of the alternation. Hence, NNN spin–spin interactions in a dimerized quantum spin chain can produce a spontaneous magnetization. On the other hand, for quantum spin chains with a spontaneous magnetization, caused by NNN spin–spin couplings, the alternation of nearest-neighbor (NN) exchange interactions can cause destruction of that magnetization and the onset of a spin gap for low-lying excitations. Alternating NN interactions produce a spin gap between two branches of low-energy excitations, and the NNN interactions yield asymmetry of the dispersion laws of those excitations, with possible minima corresponding to incommensurate structures in the spin chain.

Low Temperature Physics•Jun 1, 2009•4 citations

Quantum phase transitions for the Haldane system in higher dimensions: A mixed-spin cluster expansion approach

Masahisa Koga, Akihisa Koga

•Jan 1, 2000•0 citations
The bulk properties and impurity effect in the one-dimensional S=1/2 Heisenberg model with dimerization and next-nearest-neighbor exchange are studied by the density matrix renormalization group (DMRG) and exact diagonalization methods. This model widely covers the S=1 Heisenberg model, two-leg ladders, bond-alternating chains and the S=1/2 Heisenberg model. Almost the whole parameter space belongs to the Haldane phase. In the non-dimerizing limit a transition to a kind of spin liquid takes place, characterized by the delocalized spin polarization. This transition causes the distinct impurity effects between a spin-Peierls compound CuGeO_{3} and the Haldane systems. Experimental aspects of a bond-alternating compound CuNb_{2}O_{6} are also discussed. Furthermore, the incommensurate correlation arising in this model is extensively studied, and a phase diagram is constructed.
We study measurement-only dynamics in an interacting spin-1 chain, using forced, normalized local projections rather than Born-rule-sampled measurement outcomes. Starting from the nearest-neighbor (NN) Affleck-Kennedy-Lieb-Tasaki (AKLT) Haldane symmetry-protected topological state, we show that competing local projectors drive this order toward three distinct dynamical phases: a featureless topologically trivial product state, an explicitly dimerized valence-bond-solid state, and a topologically trivial next-nearest-neighbor (NNN) AKLT state consisting of two interwoven Haldane chains. Using matrix product state and exact statevector simulations, we identify continuous transitions among these phases and characterize them using nonlocal string order parameters, local dimer order, and entanglement scaling. For the NN-NNN AKLT model, finite-size signatures are consistent with an intervening extended critical regime rather than a single direct transition. These results extend studies of monitored topology to a bosonic SPT and show that local projections can control both topological and valence-bond-solid order.
A one-dimensional spin-1∕2 model in which the alternation of the exchange interactions between neighboring spins is accompanied by the next-nearest-neighbor (NNN) spin exchange (zig-zag spin ladder with alternation) is studied. The thermodynamic characteristics of the model quantum spin chain are obtained in the mean-field-like approximation. Depending on the strength of the NNN interactions, the model manifests either the spin-gapped behavior of low-lying excitations at low magnetic fields, or ferrimagnetic ordering in the ground state with gapless low-lying excitations. The system undergoes second-order or first-order quantum phase transitions, governed by the external magnetic field, NNN coupling strength, and the degree of the alternation. Hence, NNN spin–spin interactions in a dimerized quantum spin chain can produce a spontaneous magnetization. On the other hand, for quantum spin chains with a spontaneous magnetization, caused by NNN spin–spin couplings, the alternation of nearest-neighbor (NN) exchange interactions can cause destruction of that magnetization and the onset of a spin gap for low-lying excitations. Alternating NN interactions produce a spin gap between two branches of low-energy excitations, and the NNN interactions yield asymmetry of the dispersion laws of those excitations, with possible minima corresponding to incommensurate structures in the spin chain.