1303.4285 (M. Dressel et al.)

Charge Order Breaks Magnetic Symmetry in Molecular Quantum Spin Chains    [PDF]

M. Dressel, M. Dumm, T. Knoblauch, B. Köhler, B. Salameh, S. Yasin

Charge order affects most of the electronic properties but is believed not to alter the spin arrangement since the magnetic susceptibility remains unchanged. We present electron-spin-resonance experiments on quasi-one-dimensional (TMTTF)2X salts (X= PF6, AsF6 and SbF6), which reveal that the magnetic properties are modified below TCO when electronic ferroelectricity sets in. The coupling of anions and organic molecules rotates the g-tensor out of the molecular plane creating magnetically non-equivalent sites on neighboring chains at domain walls. Due to anisotropic Zeeman interaction a novel magnetic interaction mechanism in the charge-ordered state is observed as a doubling of the rotational periodicity of Delta H.

View original: http://arxiv.org/abs/1303.4285