2009/04/30 by Kazuo Hida, Ken'ichi Takano, Hidenori Suzuki
Physics and Astronomy · #Quantum many-body systems #Statistical Mechanics and Entropy #Theoretical and Computational Physics #cond-mat.stat-mech #cond-mat.str-el
paper · pdf · doi:10.1143/jpsj.78.084716
published as J. Phys. Soc. Jpn. 78 (2009) 084716 · 23 pages, 10 figures
openalex publication_date 2009/08/10 · arxiv created 2010/03/26 · arxiv updated 2010/03/29 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We formulate statistical mechanics for the mixed diamond chain with spins of magnitudes 1 and 1/2. Owing to a series of conservation laws, any eigenstate of this system is decomposed into eigenstates of finite odd-length spin-1 chains. The ground state undergoes five quantum phase transitions with varying the parameter λ controlling frustration. We obtain the values of the residual entropy and the Curie constant which characterize each phase and phase boundary at low temperatures. We further find various characteristic finite-temperature properties such as the nonmonotonic temperature dependence of the magnetic susceptibility, the multipeak structure in the λ-dependence of entropy, the plateau-like temperature dependence of entropy and the multipeak structure of specific heat.