Quadrupolar Effect in Strongly Correlated Systems

抄録

We have performed the ultrasonic measurement on the Kondo compound Ce_xLa_1-xB₆ and the charge fluctuation compound Yb₄As₃ to examine the quadrupolar effect. The magnetic phase diagram of Ce_xLa_1-xB₆ is discussed in connection with the competition of the intersite interactions of the quadrupolar and magnetic moments to the Kondo coupling. The elastic softening of the C₄₄ mode associated with the charge ordering in Yb₄As₃ is explained in terms of the susceptibility for the charge fluctuation mode with Γ₅ symmetry.