2005/08/29 by Bo Gu, Gang Su, Song Gao
Mathematics · Physics and Astronomy · #Algebraic structures and combinatorial models #Antiferromagnetism #Density matrix renormalization group #Ferromagnetism #Heisenberg model #Magnetic field #Magnetization #Physics of Superconductivity and Magnetism #Quantum #Quantum many-body systems #Spin (aerodynamics) #cond-mat.str-el
paper · pdf · doi:10.1088/0953-8984/17/38/012
published as J. Phys.: Condens. Matter 17, 6081(2005) · 8 pages, 9 figures, to be published in J. Phys.: Condens. Matter
arxiv created 2005/08/29 · openalex publication_date 2005/09/09 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
By means of the density matrix renormalization group (DMRG) method, the magnetic properties of the J-J-J′ quantum Heisenberg chains with spin S=1/2, 1, 3/2 and 2 in the ground states are investigated in the presence of a magnetic field. Two different cases are considered: (a) when J is antiferromagnetic and J′ is ferromagnetic (i.e. the AF-AF-F chain), the system is a ferrimagnet. The plateaus of the magnetization are observed. It is found that the width of the plateaus decreases with increasing the ferromagnetic coupling, and disappears when % J′/J passes over a critical value. The saturated field is observed to be independent of the ferromagnetic coupling; (b) when J is ferromagnetic and J′ is antiferromagnetic (i.e. the F-F-AF chain), the system becomes an antiferromagnet. The plateaus of the magnetization are also seen. The width of the plateaus decreases with decreasing the antiferromagnetic coupling, and disappears when J′/J passes over a critical value. Though the ground state properties are quite different, the magnetization plateaus in both cases tend to disappear when the ferromagnetic coupling becomes more dominant. Besides, no fundamental difference between the systems with spin half-integer and integer has been found.