The Zero-Voltage Conductance of Nanographenes: Simple Rules and Quantitative Estimates

Abstract

International audienceZero-dimensional graphenes, also called nanographenes (NGs), consist of fragments of graphene with a finite number of hexagons. NGs can be viewed as a subset of the polycyclic aromatic hydrocarbons (PAHs) that continue to attract chemists' attention. We developed a simple theory for the ballistic electron transport through NGs which combines elements of the electronic structure theory of graphene, intuitive methods for the calculation of the molecular conductance, and chemical concepts such as Kekule structures. This theory enables one to analyze the relation between the structure of NGs and their conductance. General formulas and rules for the zero-voltage conductance as a function of the contact positions are derived. These formulas and rules require at most simple paper and pencil calculations in applications to systems containing several tens of carbon atoms

Towards graphyne molecular electronics

“…Using a Landauer-Büttiker ARTICLE approach 32,34,35 , the transmission function can then be integrated for an appropriate energy window to obtain the current that would pass through the molecule at that particular bias. The path of the electron is here assumed to occur exclusively through the NH 2 ends (although formally possible in principle 36 , conduction through the weakly binding, weakly competing carbon centres is not considered). Figure 3 shows the computed transmission spectra for electron transport through the carbo-benzene A (black) and through a HBC graphene flake (red) similar to the one measured in ref.…”

Omni-conducting and omni-insulating molecules

“…[13][14][15][16][17][18][19][20][21][22] The present work is concerned with this model and the information that it may give about the interaction of the factors of contact position and molecular structure. In particular, we explore the possibility that some molecular structures may display a much reduced dependence of the predicted transmission on precise positioning of the contacts.…”

Robust conductance zeros in graphene quantum dots and other bipartite systems

“…One may start also with multi-terminal lattices as pictured in Fig.1. As example, a three-terminal naphtalene, with all T AA = 0, may be used as a builiding block to explain the DQI in perylene type lattices as those obtained in 35,36 . Finally one remarks that the second dot in Fig.…”