Quantum Dots Embedded in Graphene Nanoribbons by Chemical Substitution
The Modelization and Simulation group at CFM has been able to simulate the quantum transport properties of boron-doped graphene nanoribbons (GNRs), helping to interpret the experimental data obtained by the group of Prof. J. I. Pascual at NanoGUNE. The Figure below shows the computed transport characteristics through a pristine section of a 7-armchair GNR enclosed by two B-dimer defects situated 6.5 nm apart, mimicking the experimental situation. The results shows enhance transport at the energies corresponding to quantum well (QW) states derived from the valence band (VB). The effect is similar to that of Fabry-Perot resonances in optics. Surprisingly, the lower valence minus one (VB-1) band is almost immune to the scattering created by the B dopants and does not create any QW states at well-defined energies. This different behavior stems from the different symmetry and spatial distribution of both bands. The overall agreement with the scanning tunneling spectroscopy is remarkable.
This work was supported by the FP7 FET-ICT project PAMS (contract No. 610446), MINECO coordinated project MAT2013-46593-C6, Basque Gov. Dep. de Educación and UPV/EHU (Grant No. IT-756-13), JSPS (Grant No.15K21765) and by Swiss NSF and SNI.