A Tunable Two-impurity Kondo system in an atomic point contact
Abstract
Two magnetic atoms, one attached to the tip of a Scanning Tunneling Microscope (STM) and one adsorbed on a metal surface, each constituting a Kondo system, have been proposed as one of the simplest conceivable systems potentially exhibiting quantum critical behaviour. We have succeeded in implementing this concept experimentally for cobalt dimers clamped between an STM tip and a gold surface. Control of the tip-sample distance with sub-picometer resolution allows us to tune the interaction between the two cobalt atoms with unprecedented precision. Electronic transport measurements on this two-impurity Kondo system reveal a rich physical scenario which is governed by a crossover from local Kondo screening to non-local singlet formation due to antiferromagnetic coupling as a function of separation of the cobalt atoms.
Cite
@article{arxiv.1108.0869,
title = {A Tunable Two-impurity Kondo system in an atomic point contact},
author = {Jakob Bork and Yong-hui Zhang and Lars Diekhöner and László Borda and Pascal Simon and Johann Kroha and Peter Wahl and Klaus Kern},
journal= {arXiv preprint arXiv:1108.0869},
year = {2015}
}
Comments
22 pages, 5 figures