Inelastic sputtering of solids by ions

Abstract

We study the conductance through two types of graphene nanostructures: nanoribbon junctions in which the width changes from wide to narrow, and curved nanoribbons. In the wide-narrow structures, substantial reflection occurs from the wide-narrow interface, in contrast to the behavior of the much studied electron gas waveguides. In the curved nanoribbons, the conductance is very sensitive to details such as whether regions of a semiconducting armchair nanoribbon are included in the curved structure-such regions strongly suppress the conductance. Surprisingly, this suppression is not due to the band gap of the semiconducting nanoribbon, but is linked to the valley degree of freedom. Although we study these effects in the simplest contexts, they can be expected to occur for more complicated structures, and we show results for rings as well. We conclude that experience from electron gas waveguides does not carry over to graphene nanostructures. The interior interfaces causing extra scattering result from the extra effective degrees of freedom of the graphene structure, namely the valley and sublattice pseudospins.

Graphitic nanostripes in silicon carbide surfaces created by swift heavy ion irradiation

“…Furthermore, we follow the commonly accepted concept that electrons in the conduction band of a dielectric behave like electrons in metals 45 . Thus, we assume that the electronic heat capacity C e (T e ) can be described using the free-electron gas formalism, so that…”

Track formation in III-N semiconductors irradiated by swift heavy ions and fullerene and re-evaluation of the inelastic thermal spike model

“…By analogy to previous works [53,69], for all our calculations we will assume C e = 1 J cm -3 K -1 and K e = 2 J cm -1 s -1 K -1 , constant in time and temperature and identical for all the considered materials. The parameter q is the specific mass of the lattice and g is the electron-phonon coupling constant, which is linked to the electron mean free path (k) by g = K e /k 2 ; g = 2/k 2 when considering the assumed value of K e .…”

Behavior of crystalline silicon under huge electronic excitations: A transient thermal spike description

“…The study will be done within the framework of the inelastic thermal spike model [13,19,24,42] initially developed to describe the sensitivity of metals [43] and insulators [44] under swift heavy ion irradiation. Although this model is open to criticism [45], it is the most elaborate in providing certain quantitative predictions regarding track formation [19,42].…”