Exploring the Kondo Effect of an Extended Impurity with Chains of Co Adatoms in a Magnetic Field.

  title={Exploring the Kondo Effect of an Extended Impurity with Chains of Co Adatoms in a Magnetic Field.},
  author={Bimla Danu and Fakher F. Assaad and Fr{\'e}d{\'e}ric Mila},
  journal={Physical review letters},
  volume={123 17},
Motivated by recent STM experiments, we explore the magnetic field induced Kondo effect that takes place at symmetry protected level crossings in finite Co adatom chains. We argue that the effective two-level system realized at a level crossing acts as an extended impurity coupled to the conduction electrons of the substrate by a distribution of Kondo couplings at the sites of the chain. Using auxiliary-field quantum Monte Carlo simulations, which quantitatively reproduce the field dependence… 

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