Controlling the near-field excitation of nano-antennas with phase-change materials

• Tsung Sheng Kao,
• Yi Guo Chen and
• Ming Hui Hong

Beilstein J. Nanotechnol. 2013, 4, 632–637, doi:10.3762/bjnano.4.70

• quantitative control of the crystalline proportions of the phase-change thin film rather than the complicated manipulations of an incident light beam. This makes such a near-field energy controllable template much easier to be implemented. To analyse this hybrid plasmonic system, numerical simulations were

3D nano-structures for laser nano-manipulation

• Gediminas Seniutinas,
• Lorenzo Rosa,
• Gediminas Gervinskas,
• Etienne Brasselet and
• Saulius Juodkazis

Beilstein J. Nanotechnol. 2013, 4, 534–541, doi:10.3762/bjnano.4.62

• the patterns of such nano-wells was investigated experimentally and numerically. By doing numerical simulations of 50-nm and 100-nm diameter polystyrene beads in water and air, we show the potential of such patterns for self-induced back-action (SIBA) trapping. The best trapping conditions were found

• electron microscopy (SEM). Numerical simulations The structure was modeled as a glass substrate on which a gold layer of 100 nm thickness was patterned with a lattice of water-filled (n = 1.33) holes of 200 nm diameter. The nano-wells were placed on top of the holes as 100 nm high cylindrical gold rings

Multiple regimes of operation in bimodal AFM: understanding the energy of cantilever eigenmodes

• Daniel Kiracofe,
• Arvind Raman and
• Dalia Yablon

Beilstein J. Nanotechnol. 2013, 4, 385–393, doi:10.3762/bjnano.4.45

• bimodal AFM. A series of experiments and numerical simulations shows that the primary cause of the contrast reversals is not the choice of eigenmode itself (e.g., second versus fourth), but rather the relative kinetic energy between the higher eigenmode and the first eigenmode. This leads to the

• operating parameters, which suggest that there are actually at least three distinct operating regimes in bimodal AFM (akin to attractive/repulsive regimes in AM-AFM). Numerical simulations are then used to provide further insight into these different regimes. Experiment Methods An AFM (Asylum Research

• regime. Simulation Modeling In order to provide insight into the physical processes at work, we use numerical simulations. The VEDA simulator (a freely available, open-source, web-based [20] AFM simulator developed by the authors) is used for numerical simulation. A full description of the simulator is

Near-field effects and energy transfer in hybrid metal-oxide nanostructures

• Ulrich Herr,
• Barat Achinuq,
• Cahit Benel,
• Giorgos Papageorgiou,
• Manuel Goncalves,
• Johannes Boneberg,
• Paul Leiderer,
• Paul Ziemann,
• Peter Marek and
• Horst Hahn

Beilstein J. Nanotechnol. 2013, 4, 306–317, doi:10.3762/bjnano.4.34

• the energy-transfer experiments, together with their relevant optical properties. Then we report details of the preparation of the Ag nanoantennas. Results of numerical simulations of the electromagnetic field in the vicinity of the nanoantennas are then presented and discussed with respect to the

• light. These effects have been further explored by numerical simulations of the electromagnetic field in model structures, which will be presented in the next section. C. Numerical simulation of the electrical field distribution Numerical simulations have been performed using the COMSOL Multiphysics RF

• periodic arrays of triangular Ag nano-antennas, which have been produced by nanosphere lithography. The optical properties of the Ag nano-antennas have been investigated by numerical simulations based on solutions of Maxwell’s equations. We find large resonant enhancements of the electrical field in the

Influence of diffusion on space-charge-limited current measurements in organic semiconductors

• Thomas Kirchartz

Beilstein J. Nanotechnol. 2013, 4, 180–188, doi:10.3762/bjnano.4.18

• Thomas Kirchartz Department of Physics and Centre for Plastic Electronics, Imperial College London, South Kensington Campus SW7 2AZ, United Kingdom 10.3762/bjnano.4.18 Abstract Numerical simulations of current–voltage curves in electron-only devices are used to discuss the influence of charged

• be neglected anymore, which makes analytical approximations for this situation problematic [7][10][13]. In this article numerical simulations are used to show how the presence of traps leads to deviations from the analytical equations typically used to analyze single-carrier current–voltage curves. I

High-resolution dynamic atomic force microscopy in liquids with different feedback architectures

• John Melcher,
• David Martínez-Martín,
• Miriam Jaafar,
• Julio Gómez-Herrero and
• Arvind Raman

Beilstein J. Nanotechnol. 2013, 4, 153–163, doi:10.3762/bjnano.4.15

• the tip–sample force [1][4][8][9]. However, the optimal imaging amplitude in FM has also been considered [10]. The role of feedback control in dAFM and its stability have been studied largely by using numerical simulations to solve complex systems of nonlinear, integro-differential equations governing

Spring constant of a tuning-fork sensor for dynamic force microscopy

• Dennis van Vörden,
• Manfred Lange,
• Merlin Schmuck,
• Nico Schmidt and
• Rolf Möller

Beilstein J. Nanotechnol. 2012, 3, 809–816, doi:10.3762/bjnano.3.90

• tuning fork in qPlus configuration. The simple calculation for a rectangular cantilever is compared to the values obtained by the analysis of the thermal excitation and by the direct mechanical measurement of the force versus displacement. To elucidate the difference, numerical simulations were performed

• the deflection as a function of the applied force, the point of application has to be considered carefully. In the present experiment this was at a distance of 0.2–0.3 mm from the free end, which, according to the numerical simulations presented, leads to an increase of the observed spring constant by

Simultaneous current, force and dissipation measurements on the Si(111) 7×7 surface with an optimized qPlus AFM/STM technique

• Zsolt Majzik,
• Martin Setvín,
• Andreas Bettac,
• Albrecht Feltz,
• Vladimír Cháb and
• Pavel Jelínek

Beilstein J. Nanotechnol. 2012, 3, 249–259, doi:10.3762/bjnano.3.28

• will consider only the parasitic capacitance Cp in the rest of the discussion. For circuit analyses we performed numerical simulations with the SPICE-based analog simulation program TINA-TI [38]. The frequency response of the IVC is shown in Figure 3A. For calculations we used the macro model of Op111

An NC-AFM and KPFM study of the adsorption of a triphenylene derivative on KBr(001)

• Antoine Hinaut,
• Adeline Pujol,
• Florian Chaumeton,
• David Martrou,
• André Gourdon and
• Sébastien Gauthier

Beilstein J. Nanotechnol. 2012, 3, 221–229, doi:10.3762/bjnano.3.25

• surface dipoles with a component pointing along the normal to the surface. These findings are interpreted with the help of numerical simulations. It is shown that the surface–molecule interaction is dominated by the electrostatic interaction of the cyano groups with the K+ ions of the substrate. The

• Figure 8a. Numerical simulations To gain insight into the adsorption and dynamic properties of HCPTP on KBr(001), we performed numerical simulations, as described in the Methods section. The calculated lowest-energy adsorbed conformation of HCPTP on KBr(001) is displayed in Figure 9. The molecule is

• allow conclusions to be drawn. More extensive numerical simulations would also be necessary. The measurement of a 0.4 nm height for the MLh monolayer and the high-resolution images of Figure 7 are indicative of a structure composed of molecules lying flat on the surface. The observation of the dewetting

Theoretical study of the frequency shift in bimodal FM-AFM by fractional calculus

• Elena T. Herruzo and
• Ricardo Garcia

Beilstein J. Nanotechnol. 2012, 3, 198–206, doi:10.3762/bjnano.3.22

• agreement obtained between the numerical simulations and the results deduced from the half-derivative of the interaction force are remarkable (see insets). Because the dependencies of the force on the distance in the Lennard-Jones and DTM models are rather different, we infer that the approach deduced here

Analysis of fluid flow around a beating artificial cilium

• Mojca Vilfan,
• Gašper Kokot,
• Andrej Vilfan,
• Natan Osterman,
• Blaž Kavčič,
• Igor Poberaj and
• Dušan Babič

Beilstein J. Nanotechnol. 2012, 3, 163–171, doi:10.3762/bjnano.3.16

• angle θ from the vertical position. Their expression for the generated volume flow reads as where CN is the transverse drag coefficient from the resistive force theory and η the water viscosity. Performing numerical simulations as described in [21] and comparing the calculated volume flow rate with

Charge transfer through single molecule contacts: How reliable are rate descriptions?

• Denis Kast,
• L. Kecke and
• J. Ankerhold

Beilstein J. Nanotechnol. 2011, 2, 416–426, doi:10.3762/bjnano.2.47

• orders of magnitude less expensive than elaborate numerical simulations that, however, provide exact solutions as benchmarks. Adjustable parameters obtained, e.g., from ab initio calculations allow for the treatment of various realizations. Even though not as rigorously formulated as, e.g

• ; molecular contacts; nonequilibrium distributions; numerical simulations; rate equations; Introduction Electrical devices on the nanoscale have received substantial interest in the last decade [1]. Impressive progress has been achieved in contacting single molecules or molecular aggregates with conducting

Dense lying self-organized GaAsSb quantum dots on GaAs for efficient lasers

• Thomas H. Loeber,
• Dirk Hoffmann and
• Henning Fouckhardt

Beilstein J. Nanotechnol. 2011, 2, 333–338, doi:10.3762/bjnano.2.39

• the QDs actually consist of the alloy GaAs1−xSbx. With decreasing Sb concentration within the QDs the emission wavelength decreased. To estimate the actual Sb concentration within the QDs, numerical simulations were performed with the program nextnano3 [19]. For the calculations, the dot dimensions

• temperature, as shown for the smaller dots in the inset of Figure 4, in agreement with Forchel et al. [21]. The dot height also increased, while the dot density was almost constant at ≈6.5 × 1010 cm−2. The experimental PL data were confirmed by numerical simulations with nextnano3, revealing a decrease of the

• number density of 3.2 × 1010 cm−2. Numerical simulations with the program nextnano3 revealed a Sb concentration within the QDs of x = 0.28 (GaAs0.72Sb0.28) for the smaller dots and x = 0.52 (GaAs0.48Sb0.52) for the larger dots. Moreover, the growth temperature had a strong influence on PL emission

A collisional model for AFM manipulation of rigid nanoparticles

• Enrico Gnecco

Beilstein J. Nanotechnol. 2010, 1, 158–162, doi:10.3762/bjnano.1.19

• both cases θ(b) decreases with increasing b until the particle is lost when b > a or b > L. Furthermore, the angle θ → 90◦ when b → 0. Numerical simulations show that similar conclusions are also valid for arbitrarily thick nanorods [6], although simple analytic expressions cannot, in general, be

• under ambient conditions by tapping AFM [6][7]. Furthermore, we have also observed that, at least in the case of the nanospheres, the model goes beyond the restrictive hypothesis that the particles are immediately stopped after being released by the tip. This has been shown by numerical simulations

Review and outlook: from single nanoparticles to self-assembled monolayers and granular GMR sensors

• Alexander Weddemann,
• Inga Ennen,
• Anna Regtmeier,
• Camelia Albon,
• Annalena Wolff,
• Katrin Eckstädt,
• Nadine Mill,
• Michael K.-H. Peter,
• Jochen Mattay,
• Carolin Plattner,
• Norbert Sewald and
• Andreas Hütten

Beilstein J. Nanotechnol. 2010, 1, 75–93, doi:10.3762/bjnano.1.10

• exceeded, no further increase can be reported; the signal remains constant. In order to understand the experimental observations, the findings are compared to numerical simulations: Particles are assumed to be organized along a hexagonal grid on top of the sensor as shown in Figure 12(b); the surface