Strain enhancement of the Kondo effect in graphene

The Kondo physics of screening of an impurity's magnetic moment by electrons in doped graphene has been predicted to exhibit peculiar features. However, conclusive experimental observation of the phenomenon remains elusive. One possible obstacle to its identification is a very small Kondo temperature T_K in situations where the chemical potential lies near the Dirac point. Here, we propose to use mechanical deformations in graphene to recognize the unique fingerprints that the Kondo regime exhibits [1]. Inhomogeneous deformations are known to produce specific alternating changes in the local density of states that indicate sublattice symmetry breaking effects. These patterns can be magnified to produce significant enhancement or depression of T_K for magnetic impurities positioned at different lattice sites. The deformation-induced changes, particularly the strong increase of T_K expected at certain impurity locations, may lift the Kondo scale into the experimentally relevant range and are suitable for detection using local probes such as scanning tunneling microscopy.

[1] D. Zhai, K. Ingersent, S. E. Ulloa, and N. Sandler, Strain enhancement of the Kondo effect in graphene, arXiv:1808.08285.