Dresden 2017 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 30: Correlated Electrons: Quantum Impurities, Kondo Physics

TT 30.6: Vortrag

Dienstag, 21. März 2017, 15:15–15:30, HSZ 03

AFM mechanical dissipation due to onset of Kondo impurity screening — •Pier Paolo Baruselli, Michele Fabrizio, and Erio Tosatti — SISSA, Via Bonomea 265 34136 Trieste (Italy)

In nanomechanical systems such as STM tips approaching magnetic sites on a surfaces, some cases have been reported where the tip may cause the switching of the impurity spin from zero or one, to a spin 1/2 showing up as a Kondo conductance peak. Since at the same time one can in principle measure the tip mechanical dissipation, it is relevant to investigate theoretically what contribution will the onset of a Kondo state make to that dissipation. As a starting point we model the Kondo state as a non-interacting resonant level, showing that the dissipation, proportional to the Kondo energy, diverges roughly as the logarithm of the temperature. We then discuss extensions of our approach using an Anderson model solved by numerical renormalization group, which accounts for many-particle effects. We finally speculate about the role of a finite driving frequency.

Sponsored by ERC MODPHYSFRICT Advanced Grant No. 320796