2000/07/27 by O. P. Sushkov, J. Oitmaa, Zheng Weihong · 9 citations
Physics and Astronomy · #Advanced Condensed Matter Physics #Physics of Superconductivity and Magnetism #Theoretical and Computational Physics #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.63.104420
3 pages, 5 figures; added reference
arxiv created 2000/07/27 · openalex publication_date 2001/02/20 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We analyze the phase diagram of the frustrated Heisenberg antiferromagnet, the J1\ensuremath-J2 model, in two dimensions. Two quantum phase transitions in the model are already known: the second-order transition from the N'eel state to the spin liquid state at (J2/J1)c2\ensuremath≈0.38, and the first-order transition from the spin liquid state to the collinear state at (J2/J1)c4\ensuremath≈0.60. We have found evidence for two second-order phase transitions: the transition from the spin columnar dimerized state to the state with plaquette-type modulation at (J2/J1)c3=0.50\ifmmode±\else\textpm\fi0.02, and the transition from the simple N'eel state to the N'eel state with spin columnar dimerization at (J2/J1)c1=0.34\ifmmode±\else\textpm\fi0.04. We also present an independent calculation of (J2/J1)c2\ensuremath≈0.38 using another approach.