2002/09/10 by Kazuo Hida · 3 citations
Physics and Astronomy · #Advanced Condensed Matter Physics #Heisenberg model #Magnetization #Plateau (mathematics) #Quantum many-body systems #Randomness #Relaxation (psychology) #Spins #Symmetry (geometry) #Theoretical and Computational Physics #Translational symmetry #cond-mat.dis-nn #cond-mat.str-el
paper · pdf · doi:10.1143/jpsj.72.911
published as J. Phys. Soc. Jpn, 72, 911 (2003) · 5 pages, 9 figures, references corrected and added
arxiv created 2002/09/10 · openalex publication_date 2003/04/15 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The S=1/2 frustrated Heisenberg chains with bond alternation is known to exhibit a magnetization plateau at half of the saturation magnetization \Ms accompanied by the spontanuous translational symmetry breakdown. The effect of randomness on the magnetization process of this model is investigated. First we consider the mixture of the two kinds of chains both of which possess the \Ms/2-plateau in the common interval of the magnetization field. The plateau at \Ms/2 is found to vanish immediately if the randomness is switched on in agreement with Totsuka's prediction. The small plateau also appears near the saturation field due to the localization of inverted spins around the minority bond. On the other hand, if the stronger bond is replaced by the ferromagnetic bonds randomly, the randomness induced fractional plateau appears as in the nonfrustrated case. The plateau at \Ms/2 does not simply vanish but shifts and splits into two smaller plateaux. The magnetization on this plateau varies nonlinearly with 1-p. The physical origin of this behavior is explained based on the strong coupling picture.