We study a magnetic impurity intercalated in bilayer graphene. A representative configuration generates a hybridization function with strong dependence on the conduction-electron energy, including a full gap with one hard and one soft edge. Shifts of the chemical potential via gating or doping drive the system between non-Kondo (free-moment) and Kondo-screened phases, with strong variation of the Kondo scale. Quantum phase transitions near the soft edge are of Kosterlitz-Thouless type, while others are first order. Near the hard edge, a bound-state singlet appears inside the gap; although of single-particle character, its signatures in scanning tunneling spectroscopy are very similar to those arising from a many-body Kondo resonance.
@article{arxiv.1310.0502,
title = {Quantum phase transitions into Kondo states in bilayer graphene},
author = {Diego Mastrogiuseppe and Arturo Wong and Kevin Ingersent and Sergio Ulloa and Nancy Sandler},
journal= {arXiv preprint arXiv:1310.0502},
year = {2014}
}