2012/01/14 by Yutaka Akagi, Masafumi Udagawa, Yukitoshi Motome · 1 citation
Physics and Astronomy · #cond-mat.str-el
paper · pdf · doi:10.1103/physrevlett.108.096401
published as Phys. Rev. Lett. 108, 096401 (2012) · 5 pages, 4 figures, accepted for publication in Physical Review Letters
arxiv created 2012/01/14 · arxiv updated 2015/06/03
We reveal the significance of kinetic-driven multiple-spin interactions hidden in geometrically-frustrated Kondo lattice models. Carefully examining the perturbation in terms of the spin-charge coupling up to the fourth order, we find that a positive biquadratic interaction is critically enhanced and plays a crucial role on stabilizing a spin scalar chiral order near 1/4 filling in a triangular lattice case. This is a generalized Kohn anomaly, appearing only when the second-order perturbation is inefficient because of the degeneracy under frustration. The mechanism is potentially common to frustrated spin-charge coupled systems, leading to emergence of unusual magnetic orders.