Low-Temperature Features of Nano-Particle Dynamics

In view of better characterizing possible quantum effects in the dynamics of nanometric particles, we measure the effect on the relaxation of a slight heating cycle. The effect of the field amplitude is studied; its magnitude is chosen in order to induce the relaxation of large particles (~7nm), even at very low temperatures (100mK). Below 1K, the results significantly depart from a simple thermal dynamics scenario.