Anomalous nonadditive dispersion interactions in systems of three one-dimensional wires

Abstract

The non-additive dispersion contribution to the binding energy of three one-dimensional (1D) wires is investigated using wires modelled by (i) chains of hydrogen atoms and (ii) homogeneous electron gases. We demonstrate that the non-additive dispersion contribution to the binding energy is significantly enhanced compared with that expected from Axilrod-Teller-Muto-type triple-dipole summations and follows a different power-law decay with separation. The triwire non-additive dispersion for 1D electron gases scales according to the power law d −β , where d is the wire separation, with exponents β(r s ) smaller than 3 and slightly increasing with r s from 2.4 at r s = 1 to 2.9 at r s = 10, where r s is the density parameter of the 1D electron gas. This is in good agreement with the exponent β = 3 suggested by the leading-order charge-flow contribution to the triwire nonadditivity, and is a significantly slower decay than the ∼ d −7 behaviour that would be expected from triple-dipole summations.

First-Principles Models for van der Waals Interactions in Molecules and Materials: Concepts, Theory, and Applications

“…22 The inherent delocalization of free electrons in metals coupled with low dimensionality leads to an especially slow decay of the vdW force between metallic chains and layers as a function of their separation, 23 a modification of the conventional asymptotic behavior which dominates at very large distances (e.g., beyond 10−20 nm in bilayer graphene). 104 In this context, Misquitta et al 105,106 demonstrated that, upon closure of the band gap, semiconducting nanowires may also exhibit unconventional power-law behavior at intermediate separations, followed by asymptotic convergence to the pairwise-additive limit.…”

Physical adsorption at the nanoscale: Towards controllable scaling of the substrate-adsorbate van der Waals interaction

“…With an influence ranging from protein-drug binding to the double helix in DNA [5], the peculiar pedal adhesion in the gecko [6,7], and even cohesion in regolith and rubble-pile asteroids [8,9], these nonbonded forces are quantum mechanical in origin and arise from electrodynamic interactions between the constantly fluctuating electron clouds that characterize molecules and materials [10]. While our understanding of vdW interactions is rather complete at the smallest atomistic and the largest macroscopic scales, these pervasive forces exhibit a range of surprising and poorly understood effects at the nanoscale [10][11][12][13][14][15][16].This lack of understanding is best exemplified by recent puzzling experimental observations, which include (i) ultralong-range vdW interactions extending up to tens of nanometers into heterogeneous Si/SiO 2 dielectric interfaces [17,18], and influencing the delamination of extended graphene layers from silicon substrate [19]; (ii) complete screening of the vdW interaction between an atomic force microscope (AFM) tip and a SiO 2 surface by the presence of a single layer of graphene adsorbed on the surface [20]; (iii) superlinear sticking power laws for the physical adsorption of metallic clusters on carbon nanotubes with increasing surface area [21]; and (iv) nonlinear increases in the vdW attraction between homologous molecules and an Au(111) surface as a function of the molecular size [22]. Recently, theoretical evidence was found for exceptionally long-ranged vdW attraction between coupled low-dimensional nanomaterials with metallic character [11] or small band gap [10,14].…”

“…With an influence ranging from protein-drug binding to the double helix in DNA [5], the peculiar pedal adhesion in the gecko [6,7], and even cohesion in regolith and rubble-pile asteroids [8,9], these nonbonded forces are quantum mechanical in origin and arise from electrodynamic interactions between the constantly fluctuating electron clouds that characterize molecules and materials [10]. While our understanding of vdW interactions is rather complete at the smallest atomistic and the largest macroscopic scales, these pervasive forces exhibit a range of surprising and poorly understood effects at the nanoscale [10][11][12][13][14][15][16].…”

Influence of Pore Size on the van der Waals Interaction in Two-Dimensional Molecules and Materials

“…Arising from nonlocal electrodynamic correlations between instantaneous charge fluctuations in matter, vdW interactions are quantum mechanical in nature with an influence that spans distances (D) ranging from atomic dimensions (i.e., a fewÅ) to well beyond the nanoscale [33][34][35]. At these distances, dimensionality, local response properties, and While analytic vdW scaling laws (such as D −5 or D −4 for two parallel insulating wires or plates) are central to our understanding of infinite-size systems at asymptotic distances, rather unusual power laws have been observed in both finite and extended systems at intermediate distances relevant to the nanoscale [37][38][39][40][41][42][43][44][45]. For example, Gould et al [38] argued that the binding energy of graphite varies as D −4 for non-asymptotic interlayer separations, which differs from the asymptotic D −3 behavior analytically demonstrated by Dobson and coworkers [38,46,47]; this was later confirmed by high-level quantum mechanical calculations [39,41], which found D −4.2 for D ≈ 3−9Å.…”

“…Since the inclusion of many-body vdW interactions often leads to power laws with significant deviations from conventional pairwise predictions [37,43,[51][52][53][54][55], we now consider how an infinite-order many-body expansion of E A−ann vdW would influence the vdW scaling behavior in the presence of a pore. Under the same assumptions, we computed P A−ann vdW for the smallest (r = 1Å) and largest (r = R = 10Å) pore sizes considered above within the random phase approximation (RPA) of the ACFDT (see Supplemental Material) [56].…”