Heisenberg spin chain with random-sign couplings

• 成果类型: Article
• 署名作者: Fava, Michele; Jacobsen, Jesper Lykke; Nahum, Adam
• 署名单位: Universite PSL; Ecole Normale Superieure (ENS); Universite Paris Cite; Centre National de la Recherche Scientifique (CNRS); Universite PSL; Ecole Normale Superieure (ENS); Universite Paris Cite; Universite PSL; Sorbonne Universite; Sorbonne Universite; Universite Paris Cite; Centre National de la Recherche Scientifique (CNRS); Universite PSL; Ecole Normale Superieure (ENS)
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-12560
• DOI: 10.1073/pnas.2401292121
• 发表日期: 2024-09-03
• 关键词: renormalization-group; BEHAVIOR

摘要

We study the 1D quantum Heisenberg chain with randomly ferromagnetic or antiferromagnetic couplings [a model previously studied by approximate strong- disorder renormalization group (RG)]. We find that, at least for sufficiently large spin S , the ground state has spin glass order. The spin waves on top of this state have the dynamical exponent z = 3/2, intermediate between the values z = 1 of the antiferromagnet and z = 2 of the ferromagnet. Density matrix renormalization group (DMRG) simulations are in good agreement with the analytical results for spins S = 1 and S = 3/2. The case S = 1/2 shows large finite size effects: We suggest that this case is also ordered, but with a small ordered moment.