Breaking of cubic symmetry in rare-earth dodecaborides with dynamic charge stripes

The effect of symmetry lowering for the parameters of electron transport in rare-earth dodecaborides RB$_{12}$ (R = Ho, Er, Tm, Lu) with fcc crystal structure at temperatures $T \leqslant 150$ K has been discovered. It has been shown that the anisotropy of the magnetoresistance increases sharply at the transition to the disordered cage-glass phase below $T^* \sim 60$ K. This effect is observed in magnetic and nonmagnetic rare-earth dodecaborides, including solid solutions R$_x$Lu$_{1-x}$B$_{12}$ with high substitutional disorder. The role of the electron phase separation (charge stripes along the $\langle$110$\rangle$ direction) in these metals with open trajectories on the Fermi surface is discussed.