Heisenberg spin chain with random-sign couplings

Autor:	Fava, Michele, Jacobsen, Jesper Lykke, Nahum, Adam
Rok vydání:	2023
Předmět:	Condensed Matter - Strongly Correlated Electrons Condensed Matter - Disordered Systems and Neural Networks Condensed Matter - Statistical Mechanics
Druh dokumentu:	Working Paper
Popis:	We study the 1D quantum Heisenberg chain with randomly ferromagnetic or antiferromagnetic couplings (a model previously studied by approximate strong-disorder 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. 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. Comment: 7 pages + 14 pages appendices, 14 figures, published version
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/2312.13452 Zobrazit plný text záznamu View this record from Arxiv