1999/12/30 by Takashi Tonegawa, Tonegawa, Takashi, Kiyomi Okamoto +7
Physics and Astronomy · #FOS: Physical sciences #Magnetic properties of thin films #Physics of Superconductivity and Magnetism #Strongly Correlated Electrons (cond-mat.str-el) #Theoretical and Computational Physics #cond-mat.str-el
paper · pdf · doi:10.48550/arxiv.cond-mat/9912482
7 pages, 7 figures, 1 table; Proceedings of the workshop 'Frontiers in Magnetism', Kyoto, Oct. 1999
arxiv created 1999/12/30 · openalex publication_date 1999/12/30 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We investigate the ground state properties of an S=1/2 distorted diamond chain described by the Hamiltonian \cal H=J1∑_ℓ\(\vecS3ℓ-1⋅\vecS3ℓ +\vecS3ℓ⋅\vecS3ℓ+1)+J2\vecS3ℓ-2⋅\vecS3ℓ-1 +J3(\vecS3ℓ-2⋅\vecS3ℓ+\vecS3ℓ⋅\vecS3 ell+2)-H Sℓz\ (J1,~J2,~J3≥0), which models well a trimerized S=1/2 spin chain system Cu3Cl6(H2O)2⋅2H8C4SO2. Using an exact diagonalization method by means of the Lanczös technique, we determine the ground state phase diagram in the H=0 case, composed of the dimerized, spin fluid, and ferrimagnetic phases. Performing a degenerate perturbation calculation, we analyze the phase boundary line between the latter two phases in the J2,~J3\llJ1 limit, the result of which is in good agreement with the numerical result. We calculate, by the use of the density matrix renormalization group method, the ground state magnetization curve for the case (a) where J1=1.0, J2=0.8, and J3=0.5, and the case (b) where J1=1.0, J2=0.8, and J3=0.3. We find that in the case (b) the 2/3-plateau appears in addition to the 1/3-plateau which also appears in the case (a). The translational symmetry of the Hamiltonian \cal H is spontaneously broken in the 2/3-plateau state as well as in the dimerized state.