FisMat2017 - Submission - View

Abstract's title: Nanomechanical dissipation at a tip-induced Kondo onset
Submitting author: Pier Paolo Baruselli
Affiliation: SISSA
Affiliation Address: Via Bonomea, 265 34136 Trieste
Country: Italy
Oral presentation/Poster (Author's request): Oral presentation
Other authors and affiliations: Michele Fabrizio (SISSA), Erio Tosatti (SISSA, CNR-IOM Democritos, ICTP)
Abstract

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 by employing the time-dependent
Gutzwiller approximation.