arXiv subjects

Jia Li

Publications and source records attributed to Jia Li.

597 records · Page 34Linked to original sources

arXiv2010

Spontaneous edge-defect formation and defect-induced conductance suppression in graphene nanoribbons

We present a first-principles study of the migration and recombination of edge defects (carbon adatom and/or vacancy) and their influence on electrical conductance in zigzag graphene nanoribbons (ZGNRs). It is found that at room temperature, the adatom is quite mobile while the vacancy is almost immobile along the edge of ZGNRs. The recombination of an adatom-vacancy pair leads to a pentagon-heptagon ring defect structure having a lower energy than the perfect edge, implying that such an edge-defect can be formed spontaneously. This edge defect can suppresses the conductance of ZGNRs drastically, which provides some useful hints for understanding the observed semiconducting behavior of the fabricated narrow GNRs.

cond-mat.mes-hall↗

arXiv2009

Ambient Isotopic Meshing of Implicit Algebraic Surface with Singularities

A complete method is proposed to compute a certified, or ambient isotopic, meshing for an implicit algebraic surface with singularities. By certified, we mean a meshing with correct topology and any given geometric precision. We propose a symbolic-numeric method to compute a certified meshing for the surface inside a box containing singularities and use a modified Plantinga-Vegter marching cube method to compute a certified meshing for the surface inside a box without singularities. Nontrivial examples are given to show the effectiveness of the algorithm. To our knowledge, this is the first method to compute a certified meshing for surfaces with singularities.

cs.CG↗

arXiv2005

Selective adsorption of first-row atoms on boron nitride nanotubes: the effect of localized states

First-principles calculations reveal that the adsorption of representative first-row atoms with different electronegativity, such as lithium (Li), carbon (C) and fluorine (F), on zigzag single-walled boron nitride nanotubes (BNNTs) exhibits surprising selectivity. The adsorption energy and adsorption site are dependent upon the chemical activity of adsorbate with respect to the B and N atoms in the host tube. In detail, the F atom prefers to be adsorbed on the top of the B atom, the C atom is energetically favorable to stay on the bridge site which is perpendicular to the tube-axis, and the Li atom hardly adheres to the tube (an endothermal reaction). The adsorption behavior of these three types of elements on BNNTs is elucidated based on the frontier molecular orbital theory. In addition, the mechanism of modification of electronic structures of BNNTs by adsorption is probed, and a feasible approach is proposed to tailor the electronic properties of BNNTs.

cond-mat.mtrl-sci↗