| Full text | |
| Author(s): |
Ruiz-Tijerina, David A.
;
da Silva, Luis G. G. V. Dias
Total Authors: 2
|
| Document type: | Journal article |
| Source: | PHYSICAL REVIEW B; v. 95, n. 11, p. 11-pg., 2017-03-06. |
| Abstract | |
Localized magnetic moments have been predicted to develop in graphene samples with vacancies or adsorbates. The interplay between such magnetic impurities and graphene's Dirac quasiparticles leads to remarkable many-body phenomena, which have, so far, proved elusive to experimental efforts. In this article we study the thermodynamic, spectral, and transport signatures of quantum criticality and Kondo physics of a dilute ensemble of atomic impurities in graphene. We consider vacancies and adatoms that either break or preserve graphene's C-3v and inversion symmetries. In a neutral graphene sample, all cases display symmetry-dependent quantum criticality, leading to enhanced impurity scattering for asymmetric impurities, in a manner analogous to bound-state formation by nonmagnetic resonant scatterers. Kondo correlations emerge only in the presence of a back gate, with estimated Kondo temperatures well within the experimentally accessible domain for all impurity types. For symmetry-breaking impurities at charge neutrality, quantum criticality is signaled by T-2 resistivity scaling, leading to full insulating behavior at low temperatures, while low-temperature resistivity plateaus appear both in the noncritical and Kondo regimes. By contrast, the resistivity contribution from symmetric vacancies and hollow-site adsorbates vanishes at charge neutrality and for arbitrary back-gate voltages, respectively. This implies that local probing methods are required for the detection of both Kondo and quantum critical signatures in these symmetry-preserving cases. (AU) | |
| FAPESP's process: | 16/18495-4 - Electronic transport and correlation effects in topological materials |
| Grantee: | Luis Gregório Godoy de Vasconcellos Dias da Silva |
| Support Opportunities: | Regular Research Grants |