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

Physica B Condensed Matter

Generation of ferromagnetic bonds in disordered antiferromagnetic spin-1 chains with biquadratic couplings

Kun Yang, R. N. Bhatt

Published Jan 1, 1999• 3 citations
Publisher
DOI
10.1016/s0921-4526(98)00994-6

Related papers

Generation of Ferromagnetic Couplings in a Spin-1 Chain with Random Antiferromagnetic Couplings

R. N. Bhatt, Kun Yang

APS•Mar 1, 1998•0 citations

Generation of Large Moments in a Spin-1 Chain with Random Antiferromagnetic Couplings

Kun Yang, R. N. Bhatt

We study the spin-1 chain with nearest neighbor couplings that are rotationally invariant, but include both Heisenberg and biquadratic exchange, with random strengths. We demonstrate, using perturbative renormalization group methods as well as exact diagonalization of clusters, that the system generates ferromagnetic couplings under certain circumstances even when all the bare couplings are antiferromagnetic. This disorder induced instability leads to formation of large magnetic moments at low temperatures, and is a purely quantum mechanical effect that does not have a classical counterpart. The physical origin of this instability, as well as its consequences, are discussed.

arXiv:cond-mat/9712252•Physical Review Letters•May 18, 1998•17 citations

Disordered Quantum Spin Chains with Long-Range Antiferromagnetic Interactions

N. Moure, Hyun‐Yong Lee, Stephan Haas +2 more

Bulletin of the American Physical Society•Mar 8, 2018•0 citations

Non-Heisenberg couplings and ferromagnetic instability in a random antiferromagnetic spin-1 chain

R. N. Bhatt, Kun Yang

A random antiferromagnetic spin-1 chain with both Heisenberg and biquadratic nearest neighbor couplings is found to exhibit a novel ferromagnetic-like instability at low energies, if there is competition between the Heisenberg and biquadratic couplings, even though each individual nearest neighbor coupling is such as to produce a singlet ground state for the isolated pair. This instability leads to the generation of ferromagnetic couplings, and thus to the formation of weakly coupled large moments at low temperatures. A perturbative calculation (up to 4th order) is performed to investigate whether such a situation is physically realizable in spin-1 systems.

Journal of Applied Physics•Jun 1, 1998•7 citations

Phase Diagrams of Random Antiferromagnetic Spin-1 Chains

R. A. Hyman, Kun Yang

APS•Mar 1, 2001•0 citations

Random antiferromagnetic spin- 12 chains with competing interactions

Eddy Yusuf, Kun Yang

We study disordered antiferromagnetic spin-$\frac{1}{2}$ chains with nearest- and further-neighbor interactions using the real-space renormalization-group method. We find that the system supports two different phases, depending on the ratio of the strength between nearest-neighbor and further-neighbor interactions as well the bond randomness strength. For weak further-neighbor coupling the system is in the familiar random singlet phase, while stronger further-neighbor coupling drives the system to a large spin phase similar to that found in the study of random antiferromagnetic-ferromagnetic spin chains. The appearance of the large spin phase in the absence of ferromagnetic coupling is due to the frustration introduced by further-neighboring couplings, and is unique to the disordered chains.

arXiv:cond-mat/0303201•Physical review. B, Condensed matter•Jul 30, 2003•18 citations
We study the spin-1 chain with nearest neighbor couplings that are rotationally invariant, but include both Heisenberg and biquadratic exchange, with random strengths. We demonstrate, using perturbative renormalization group methods as well as exact diagonalization of clusters, that the system generates ferromagnetic couplings under certain circumstances even when all the bare couplings are antiferromagnetic. This disorder induced instability leads to formation of large magnetic moments at low temperatures, and is a purely quantum mechanical effect that does not have a classical counterpart. The physical origin of this instability, as well as its consequences, are discussed.
A random antiferromagnetic spin-1 chain with both Heisenberg and biquadratic nearest neighbor couplings is found to exhibit a novel ferromagnetic-like instability at low energies, if there is competition between the Heisenberg and biquadratic couplings, even though each individual nearest neighbor coupling is such as to produce a singlet ground state for the isolated pair. This instability leads to the generation of ferromagnetic couplings, and thus to the formation of weakly coupled large moments at low temperatures. A perturbative calculation (up to 4th order) is performed to investigate whether such a situation is physically realizable in spin-1 systems.
We study disordered antiferromagnetic spin-12\frac{1}{2}21​ chains with nearest- and further-neighbor interactions using the real-space renormalization-group method. We find that the system supports two different phases, depending on the ratio of the strength between nearest-neighbor and further-neighbor interactions as well the bond randomness strength. For weak further-neighbor coupling the system is in the familiar random singlet phase, while stronger further-neighbor coupling drives the system to a large spin phase similar to that found in the study of random antiferromagnetic-ferromagnetic spin chains. The appearance of the large spin phase in the absence of ferromagnetic coupling is due to the frustration introduced by further-neighboring couplings, and is unique to the disordered chains.