Effect of electric fields in low-dimensional materials: Nanofrictional response as a case study
Florian Belviso, Antonio Cammarata, Jamil Missaoui, Tomáš Polcar
Abstract
A proper control of nanoscale friction is mandatory for the fabrication and operation of optimal nanoengineered devices. In this respect, the use of electric fields looks to be promising, since they are able to alter the frictional response without imprinting permanent deformations into the structure. To this aim, we perform ab initio simulations to study the microscopic mechanisms governing friction in low-dimensional materials in the presence of electrostatic fields. We consider ${\mathrm{MX}}_{2}$ transition metal dichalcogenides as a case study. By applying an electric field along an axis orthogonal to the atom layers, we induce a transfer of charge along the same axis; this transfer modifies the interatomic forces, leading, in general, to easier relative layer motion. The reported outcomes constitute a starting point to study the effect of the field direction on the intrinsic friction in future investigations. Finally, the present results can be used to predict the preferential electronic redistribution in nanostructured devices where metal-to-insulator transitions may occur in working conditions.