Observation of dynamic charge stripes in Tm0.19Yb0.81B12 at the metal-insulator transition

cond-mat.str-el

/ Authors

N. E. Sluchanko, A. N. Azarevich, A. V. Bogach, N. B. Bolotina, V. V. Glushkov, S. V. Demishev, A. P. Dudka, O. N. Khrykina, V. B. Filipov, N. Yu. Shitsevalova

and 5 more authors

G. A. Komandin, A. V. Muratov, Yu. A. Aleshchenko, E. S. Zhukova, B. P. Gorshunov

/ Abstract

Higher accuracy low temperature charge transport measurements in combination with precise X-ray diffraction experiment have allowed detecting the symmetry lowering in the single domain Tm0.19Yb0.81B12 crystals of the family of dodecaborides with metal-insulator transition. Basing on the fine structure analysis we discover formation of dynamic charge stripes within the semiconducting matrix of Tm0.19Yb0.81B12. The charge dynamics in these metallic nano-size conducting channels is characterized by broad-band optical spectroscopy that allowed estimating the frequency (~2.4 10^11 Hz) of quantum motion of the charge carriers. It is suggested that caused by cooperative Jahn-Teller effect in the boron sub-lattice, the large amplitude rattling modes of the Tm and Yb ions are responsible for modulation of the conduction band along [110] direction through the variation of 5d-2p hybridization of electron states.