@article{37d6f1d7a45148dab22968bdc27b1e17,
title = "Ca 2Y 2Cu 5O 10: The first frustrated quasi-1d ferromagnet close to criticality",
abstract = "Ca 2Y 2Cu 5O 10 is built up from edge-shared CuO 4 plaquettes forming spin chains. From inelastic neutron scattering data we extract an in-chain nearest-neighbor exchange J 1-170K and the frustrating next-neighbor J 232K interactions, both significantly larger than previous estimates. The ratio α=|J 2/J 1|=0.19±0.01 places the system close to the critical point α c=0.25 of the J 1-J 2 chain but in the 1D ferromagnetic regime. We establish that the vicinity to criticality only marginally affects the dispersion and coherence of the spin-wave-like magnetic excitations but instead results in a dramatic T dependence of high-energy Zhang-Rice singlet excitation intensities.",
author = "Kuzian, {R. O.} and S. Nishimoto and Drechsler, {S. L.} and J. M{\'a}lek and S. Johnston and {Van Den Brink}, Jeroen and M. Schmitt and H. Rosner and M. Matsuda and K. Oka and H. Yamaguchi and T. Ito",
year = "2012",
month = sep,
day = "14",
doi = "10.1103/PhysRevLett.109.117207",
language = "English",
volume = "109",
journal = "Physical Review Letters",
issn = "0031-9007",
publisher = "American Physical Society",
number = "11",
}