2006/12/31 by H. D. Rosales, D. C. Cabra, M. D. Grynberg +2
Physics and Astronomy · #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #Quantum many-body systems #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.75.174446
published as Phys. Rev. B 75, 174446 (2007) · Numerical analysis improved, 4 figures added. Final version to appear in Phys. Rev. B
arxiv created 2007/04/13 · openalex publication_date 2007/05/31 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We analyze the effects of a trimerized modulation in a quantum spin S=(1)/(2) zigzag ladder at the magnetization plateau M=1∕3. Such periodicity is argued to be stemmed from lattice deformations by phonons. The interplay between frustration and exchange modulation is well described by an effective triple sine-Gordon field theory close to the homogeneous ladder and by block-spin perturbation theory in the weakly coupled trimer regime. The characteristic triple degeneracy of the ground state for homogeneous ladders gives place to modulation driven quantum phase transitions, leading to a rich phase diagram including up-up-down, quantum plateau, and gapless plateau states.