Parallel scanning tunneling microscopy imaging of low dimensional nanostructures

Abstract

A first generation of parallel scanning tunneling microscopy ͑STM͒ simulator has been developed to accelerate the production of high quality STM images. An efficient master-slave parallel scheme has been constructed specially suited for large scale problems in which the amount of data communications remains a small fraction of the entire calculation. We apply the new parallel scheme to two examples, benzene adsorption on a metal surface and standing wave patterns on the Cu͑111͒ surface, highlighting the efficiency of our approach.

C60adsorption on theSi(111)-p(7×Rurali1, Cuadrado2, Cerdá3 2010Phys. Rev. B17072View full textAdd to dashboardCite

“…III B have been calculated with the GREEN code. 25,26 Tip and sample are modeled at the atomic level as two semi-infinite bulklike blocks. The sample is a ͑111͒-oriented Si bulk on top of which the reconstructed ͑7 ϫ 7͒ surface plus the C 60 molecule are stacked following the DFT derived geometry.…”

Adsorption and STM imaging of polycyclic aromatic hydrocarbons on graphene

“…Whereas ab initio DFT calculations could potentially give a more accurate description of the electronic structure of the system [35][36][37][38][39] compared to the semiempirical extended Hückel approximation implemented in ESQC, STM simulations in the Tersoff-Hamann approximation are rather crude since the STM tip is merely modeled as a sphere with a single s-wave state. The advantage of the ESQC method lies in allowing for the simultaneous description of the surface, the adsorbates in the tunneling junction, the tip apex, and the tip bulk as well as the explicit treatment of the tunneling current.…”

Lowest order in inelastic tunneling approximation: Efficient scheme for simulation of inelastic electron tunneling data

“…Therefore, they can be calculated independently for the sample surface and each of the tips to be considered and stored in disk as a function of energy and k points. 32 During the actual STS/IETS simulation, these vectors will be read in together with the H αβ and M λ αβ matrices corresponding to the desired tip-sample relative displacement.…”