Unveiling the nature of atomic defects in graphene on a metal surface

• Karl Rothe,
• Nicolas Néel and
• Jörg Kröger

Beilstein J. Nanotechnol. 2024, 15, 416–425, doi:10.3762/bjnano.15.37

• intact graphene sheet. Spatially resolved spectroscopy of the differential conductance and the measurement of total-force variations as a function of the lateral and vertical probe–defect distance corroborate the different character of the defects. The tendency of the vacancy defect to form a chemical

• are indeed lacking the graphene atomic lattice structure in their interior. Spatially resolved spectroscopy of the differential conductance (dI/dV, I: tunneling current, V: bias voltage) and of the tuning fork resonance frequency change (Δf) further unravel marked differences between these two kinds

Josephson dynamics and Shapiro steps at high transmissions: current bias regime

• Artem V. Galaktionov and
• Andrei D. Zaikin

Beilstein J. Nanotechnol. 2024, 15, 51–56, doi:10.3762/bjnano.15.5

• steps as compared to that observed in the Ohmic limit. Results and Discussion Below, we are going to consider a purely ballistic SNS nanojunction with fully transparent conducting channels and normal state conductance 1/RN = . The thickness of a normal (N) layer d between two superconducting (S

Spatial variations of conductivity of self-assembled monolayers of dodecanethiol on Au/mica and Au/Si substrates

• Julian Skolaut,
• Jędrzej Tepper,
• Federica Galli,
• Wulf Wulfhekel and
• Jan M. van Ruitenbeek

Beilstein J. Nanotechnol. 2023, 14, 1169–1177, doi:10.3762/bjnano.14.97

• sample plane, this leads to larger variations in the local normal force when the tip lands on a slope. Therefore, the rougher topography is likely influencing the occurrence of high- and low-current areas. More specifically, this means that the conductance can appear higher on slopes and rough surfaces

• the surface topography, the conductance obtained from averaging over random points on the surface [12][21][22][23][24] is prone to incorrect averaging. The lateral variation of the conductive properties limits strongly the amount of lateral probe positions over which measurements of such

• QI™ mode, the probe measures force and conductance curves at a raster of points on the surface, shown here for a row along the x direction. The probe is moved from pixel to pixel in a retracted position far away from the surface. At each point, a force–distance curve is measured while simultaneously

Thermal transport in kinked nanowires through simulation

• Alexander N. Robillard,
• Graham W. Gibson and
• Ralf Meyer

Beilstein J. Nanotechnol. 2023, 14, 586–602, doi:10.3762/bjnano.14.49

• Alexander N. Robillard Graham W. Gibson Ralf Meyer Bharti School of Engineering and Computer Science, Laurentian University, Sudbury P3E 2C6, Canada 10.3762/bjnano.14.49 Abstract The thermal conductance of nanowires is an oft-explored quantity, but its dependence on the nanowire shape is not

• completely understood. The behaviour of the conductance is examined as kinks of varying angular intensity are included into nanowires. The effects on thermal transport are evaluated through molecular dynamics simulations, phonon Monte Carlo simulations and classical solutions of the Fourier equation. A

• have been achieved [17][18][19][20]. We have also seen investigations into corrugated nanowires, where a jagged or sinusoidal pattern is inscribed into the edges of the wire [21][22]. In such engineered systems, it is common that there is a decrease in thermal conductance. There is a lack of free paths

Molecular nanoarchitectonics: unification of nanotechnology and molecular/materials science

• Katsuhiko Ariga

Beilstein J. Nanotechnol. 2023, 14, 434–453, doi:10.3762/bjnano.14.35

• intermediates, and the final product were identified in situ by differential conductance imaging using a CO-modified tip. The bias voltage was set above the lowest unoccupied molecular orbital energy and the probe was placed over the C–Br bond, which was then broken. After the reaction, a dip appeared on the

• remove the second bromine atom. Close-up observation of the structure showed that the molecule was fully debrominated. Differential conductance imaging confirmed that the molecular skeleton, including the two naphthalene moieties, was clearly resolved. It was also observed that the two naphthalene

• tip was brought close enough to obtain a single-atom conductance gap, it was retracted and silicon atoms were removed. A perpendicular magnetic field was applied to explore physical phenomena such as Kondo resonance. The nanoarchitectonics of magnetic topological states due to spin polarization in

A distributed active patch antenna model of a Josephson oscillator

• Vladimir M. Krasnov

Beilstein J. Nanotechnol. 2023, 14, 151–164, doi:10.3762/bjnano.14.16

• slots cancel out [34][36][39] and the radiative impedance becomes real. Therefore, at the resonance the radiation power from one slot is where |v(0,a)| is the amplitude of voltage oscillations at the slot (x = 0,a) and G1 is the radiative conductance of the single slot. Low-Tc JJs are operating at sub

• -terahertz frequencies, for which the wavelength in free space is large, λ0 ≫ b ≫ d. In this limit [36][39], where Z0 = ≃ 376.73 (Ω) is the impedance of free space. To calculate the total radiation power from both slots one has to take into account the mutual radiative conductance, G12, and the array factor

• mode, the argument of J0 becomes (c0/c)πnsinΘ. Since c0 ≪ c, k0a is small. Expanding in Equation 6, J0(x) ≃ 1 − x2/4 (for x ≪ 1), we obtain: It is seen that the mutual conductance for a JJ with thin electrodes (slow c0) is not negligible and can be as big as the single-slot conductance G1, Equation 5

Cooper pair splitting controlled by a temperature gradient

• Dmitry S. Golubev and
• Andrei D. Zaikin

Beilstein J. Nanotechnol. 2023, 14, 61–67, doi:10.3762/bjnano.14.7

• the energy gap inside the superconductor, see Figure 1b. Unlike CAR, EC does not produce entangled electrons. In the zero-temperature limit, CAR and EC contributions to the low-bias non-local conductance of an NSN device cancel each other in the limit of low-transparency barriers [4]. In contrast, at

• introduced the non-local conductance in the limit of zero temperature and zero bias voltage, being the normal state resistance of a superconducting island [25], as well as the parameters and the local Fano factors for two barriers in the Andreev reflection regime At zero bias voltages V1 = V2 = 0, we obtain

Observation of collective excitation of surface plasmon resonances in large Josephson junction arrays

• Roger Cattaneo,
• Mikhail A. Galin and
• Vladimir M. Krasnov

Beilstein J. Nanotechnol. 2022, 13, 1578–1588, doi:10.3762/bjnano.13.132

• not seen for smaller N. To quantify the step amplitude, ΔI, at small N we plot the differential conductance, dI/dV. Figure 5b shows the dI/dV(I) curves for the I–Vs from Figure 5a, normalized by the resonant voltage Vstep. This quantity does not depend on the number of active JJs. A current step in

• array at the main resonance. Figure 8b shows the step amplitude as a function of the number of active JJs for this resonance. Blue symbols represent ΔI measured directly from the I–V characteristics. Orange symbols are obtained by integration of the areas of the peak in differential conductance, taken

• and gradual evolution of several steps with increasing N. Edges of three distinct resonant steps are indicated by dashed green lines. (a) Parts of the V–I curves near the main resonance for the meander array with different number of active JJs, N. (b) Normalized differential conductance for the I–V

From a free electron gas to confined states: A mixed island of PTCDA and copper phthalocyanine on Ag(111)

• Alfred J. Weymouth,
• Emily Roche and
• Franz J. Giessibl

Beilstein J. Nanotechnol. 2022, 13, 1572–1577, doi:10.3762/bjnano.13.131

• helpful discussions and O. Gretz for determining the preparation procedure for the mixed phase. Funding We would like to thank the German Research Foundation (”Locally mapping conductance and potential energy of a donor-acceptor system”, project number 397771090) for funding.

Experimental and theoretical study of field-dependent spin splitting at ferromagnetic insulator–superconductor interfaces

• Peter Machon,
• Michael J. Wolf,
• Detlef Beckmann and
• Wolfgang Belzig

Beilstein J. Nanotechnol. 2022, 13, 682–688, doi:10.3762/bjnano.13.60

• from a first-order to a second-order phase transition for large spin mixing angles. The experimentally found differential conductance of an EuS-Al heterostructure is compared with the theoretical calculation. With the assumption of a uniform spin mixing angle that depends on the externally applied

• on the internal spin-degrees of freedom (spin mixing angles [29]), since the conductance is zero, in contrast to a metallic ferromagnet. The absence of conductance-related parameters (transmission and polarization of each channel) strongly simplifies the boundary condition to a ferromagnetic

• an oxide layer. The normal layer acts as the tunnel probe to measure the differential conductance of the superconductor and is assumed not to influence the system properties. Since the size of the detector electrode is not small (unlike the tip of a scanning tunneling microscope) and the FI affects

Comparative molecular dynamics simulations of thermal conductivities of aqueous and hydrocarbon nanofluids

• Adil Loya,
• Antash Najib,
• Fahad Aziz,
• Asif Khan,
• Guogang Ren and
• Kun Luo

Beilstein J. Nanotechnol. 2022, 13, 620–628, doi:10.3762/bjnano.13.54

• ]. The key difference was that kerosene was used as a nonaqueous fluid, whereas in the present study paraffin (eicosane, i.e., C20H42) was used. Nevertheless, in their study, partially ionic systems demonstrated a higher increase in thermal conductance than kerosene-based systems. Therefore, our study

The role of sulfonate groups and hydrogen bonding in the proton conductivity of two coordination networks

• Ali Javed,
• Felix Steinke,
• Stephan Wöhlbrandt,
• Hana Bunzen,
• Norbert Stock and
• Michael Tiemann

Beilstein J. Nanotechnol. 2022, 13, 437–443, doi:10.3762/bjnano.13.36

• observed (see Supporting Information File 1, Figure S3 and Figure S4). The Nyquist plots show depressed semicircles in the high-frequency region (i.e., region of low Re(Z)) that allow for the determination of the proton conductance by fitting an appropriate equivalent circuit model. Here, the model

• maximum in the region from 103 to 104 Hz remains. The phase angle for the Pb-MOF sample shows only one maximum (at ca. 102 Hz) both before and after activation. We conclude that the second conductance mode in the non-activated Mg-CP material may be caused by interparticle water adsorbate layers that are

• successfully and irreversibly removed by activation. These findings are quite helpful, as they allow us to conversely conclude that the remaining mode of proton conductance is probably not caused by such adsorbate layers, but more likely occurs within the crystalline material, as will be elaborated in more

Impact of device design on the electronic and optoelectronic properties of integrated Ru-terpyridine complexes

• Max Mennicken,
• Sophia Katharina Peter,
• Corinna Kaulen,
• Ulrich Simon and
• Silvia Karthäuser

Beilstein J. Nanotechnol. 2022, 13, 219–229, doi:10.3762/bjnano.13.16

• of gold nanoparticles and contacted by nanoelectrodes. The resulting small-area nanodevices were thoroughly electrically characterized as a function of temperature and light exposure. Differences in the resulting device conductance could be attributed to the device design and the respective transport

• mechanism, that is, thermally activated hopping conduction in the case of Ru-terpyridine wire devices or sequential tunneling in nanoparticle-based devices. Furthermore, the conductance switching of nanoparticle-based devices upon 530 nm irradiation was attributed to plasmon-induced metal-to-ligand charge

• transfer in the Ru-terpyridine complexes used as switching ligands. Finally, our results reveal a superior device performance of nanoparticle-based devices compared to molecular wire devices based on Ru-terpyridine complexes as functional units. Keywords: conductance switching; gold nanoparticles

Topographic signatures and manipulations of Fe atoms, CO molecules and NaCl islands on superconducting Pb(111)

• Carl Drechsel,
• Philipp D’Astolfo,
• Jung-Ching Liu,
• Thilo Glatzel,
• Rémy Pawlak and
• Ernst Meyer

Beilstein J. Nanotechnol. 2022, 13, 1–9, doi:10.3762/bjnano.13.1

• realization of MZMs in two dimensions has been also observed in vortex cores on a proximitized topological insulator surface [19][20], in iron-based superconductors [7][21][22] or hybrid van der Waals heterostructures [23]. The fingerprint for MZMs in conductance measurements through the nanowire or in

• scanning tunneling spectroscopy (STS) is a zero-bias conductance peak occurring at boundaries and defects. Unfortunately, other structural peculiarities can also mimic such zero-bias anomalies, which eventually leads to severe misinterpretations. Therefore, the latest advances in scanning tunneling

Design aspects of Bi₂Sr₂CaCu₂O_8+δ THz sources: optimization of thermal and radiative properties

• Mikhail M. Krasnov,
• Natalia D. Novikova,
• Roger Cattaneo,
• Alexey A. Kalenyuk and
• Vladimir M. Krasnov

Beilstein J. Nanotechnol. 2021, 12, 1392–1403, doi:10.3762/bjnano.12.103

• -heating in Bi-2212 mesa structures has been extensively studied [28][29][30][31][32][33][34][35][36][37][38][39]. Although Tc of Bi-2212 may be quite high, up to ≃95 K [28], self-heating is substantial due to the low heat conductance of superconductors. Self-heating limits the maximum bias voltage that

• [44]. In contrast, the epoxy used for gluing Bi-2212 crystals has a poor heat conductance at low T. We do not consider its T-dependence because it acts just as a heat blocking layer, which we assume to have κe = 0.0025 W·K−1·m−1. However, it is necessary to take into account actual κ(T) dependencies

Two dynamic modes to streamline challenging atomic force microscopy measurements

• Alexei G. Temiryazev,
• Andrey V. Krayev and
• Marina P. Temiryazeva

Beilstein J. Nanotechnol. 2021, 12, 1226–1236, doi:10.3762/bjnano.12.90

• parachuting and sticking (Figure 2a). Figure 2a and Figure 2b show the top of a micropipette, which is a probe in scanning ion conductance microscopy [25]. From Figure 2b, we can estimate that the diameter of the intact micropipette at its most protruding part is about 100 nm. To do this, we need to make a

Impact of electron–phonon coupling on electron transport through T-shaped arrangements of quantum dots in the Kondo regime

• Patryk Florków and
• Stanisław Lipiński

Beilstein J. Nanotechnol. 2021, 12, 1209–1225, doi:10.3762/bjnano.12.89

• Patryk Florkow Stanislaw Lipinski Department of Theory of Nanostructures, Institute of Molecular Physics, Polish Academy of Sciences, M. Smoluchowskiego 17, 60-179 Poznań, Poland 10.3762/bjnano.12.89 Abstract We calculate the conductance through strongly correlated T-shaped molecular or quantum

• in the linear conductance [23][24][27][28]. There are also reports on T-shaped carbon nanotube structures [29][30] and similar carbon devices engineered by attaching C60 buckyballs onto the sidewall of a single-walled carbon nanotube (carbon nanobud [31]). Many experiments showed that Kondo and Fano

• systems close to the unitary Kondo limit. However, due to its simplicity, this approach is also often used in analysis of the linear conductance of systems with weakly broken symmetry giving results in a reasonable agreement with experiment and with numerical renormalization group calculations [67]. Mean

A Au/CuNiCoS₄/p-Si photodiode: electrical and morphological characterization

• Adem Koçyiğit,
• Adem Sarılmaz,
• Teoman Öztürk,
• Faruk Ozel and
• Murat Yıldırım

Beilstein J. Nanotechnol. 2021, 12, 984–994, doi:10.3762/bjnano.12.74

• p-type Si by measuring I–V and C–V characteristics. The fabricated Au/CuNiCoS4/p-Si device exhibited good rectifying properties, high photoresponse activity, low series resistance, and high shunt resistance. The C–V characteristics revealed that capacitance and conductance of the photodiode are

• attributed to interface states [38][39]. The conductance–voltage (G–V) graphs of the Au/CuNiCoS4/p-Si photodiode for different frequencies are displayed in Figure 10. Again, the conductance values did not change in the accumulation and depletion regions. However, the conductance values change in the

• inversion region. The conductance values for frequency values higher than 100 kHz increased suddenly and stayed almost constant towards regions of higher inversion. Furthermore, the conductance values increased with increasing frequency in the inversion region due to effect of the interface states in the

Molecular assemblies on surfaces: towards physical and electronic decoupling of organic molecules

• Sabine Maier and
• Meike Stöhr

Beilstein J. Nanotechnol. 2021, 12, 950–956, doi:10.3762/bjnano.12.71

• tip of a scanning probe microscope and mechanically lifted from the metallic surface such that they hang freely between metal contacts. This manipulation technique allows for measuring, amongst others, the electronic conductance, magnetic properties, reversible switching, and electroluminescence of

Electromigration-induced formation of percolating adsorbate islands during condensation from the gaseous phase: a computational study

• Alina V. Dvornichenko,
• Vasyl O. Kharchenko and
• Dmitrii O. Kharchenko

Beilstein J. Nanotechnol. 2021, 12, 694–703, doi:10.3762/bjnano.12.55

• substrate, then the electrical conductance will vary as the thickness of the system will vary along the direction of the applied electric field for a multilayer thick absorbate islands on a substrate system. There will be current crowding at the base of the islands and the electric field needs to be

A review of defect engineering, ion implantation, and nanofabrication using the helium ion microscope

• Frances I. Allen

Beilstein J. Nanotechnol. 2021, 12, 633–664, doi:10.3762/bjnano.12.52

Local stiffness and work function variations of hexagonal boron nitride on Cu(111)

• Abhishek Grewal,
• Yuqi Wang,
• Matthias Münks,
• Klaus Kern and
• Markus Ternes

Beilstein J. Nanotechnol. 2021, 12, 559–565, doi:10.3762/bjnano.12.46

• = 3.7 V) STM topography of h-BN/Cu(111) and the bare Cu(111) surface. Blue circles and red rings mark exemplary valley and rim areas, respectively. (c.) Differential conductance dI/dV spectra taken at rim (red line) and valley (blue line) sites and at the bare Cu(111) substrate (dashed black line). STM

• /AFM characterisation of a h-BN/Cu(111) Moiré superstructure. (a., b.) Constant-current topography at I = 500 pA and V = 3.6 V (top) or V = 5 mV (bottom). (c., d.) Simultaneously measured differential conductance (dI/dV) maps (Vmod = 10 mV (top) and Vmod = 1 mV (bottom). (e., f.) Frequency shift (Δf

Determining amplitude and tilt of a lateral force microscopy sensor

• Oliver Gretz,
• Alfred J. Weymouth,
• Thomas Holzmann,
• Korbinian Pürckhauer and
• Franz J. Giessibl

Beilstein J. Nanotechnol. 2021, 12, 517–524, doi:10.3762/bjnano.12.42

• Forschungsgemeinschaft (grant number 397771090, “Locally mapping conductance and potential energy of a donor-acceptor system”) for funding.

The nanomorphology of cell surfaces of adhered osteoblasts

• Christian Voelkner,
• Mirco Wendt,
• Regina Lange,
• Max Ulbrich,
• Martina Gruening,
• Susanne Staehlke,
• Barbara Nebe,
• Ingo Barke and
• Sylvia Speller

Beilstein J. Nanotechnol. 2021, 12, 242–256, doi:10.3762/bjnano.12.20

• present a comprehensive characterization of the 3D nanomorphology of living, as well as fixed, osteoblastic cells using scanning ion conductance microscopy (SICM), which is a nanoprobing method that largely avoids mechanical perturbations. Dynamic ruffles are observed, manifesting themselves in

• capability of apical membrane features and fluctuation dynamics in aiding the assessment of adhesion and migration properties on a single-cell basis. Keywords: cell adhesion; membrane fluctuations; osteoblast; plasma membrane nanomorphology; scanning ion conductance microscopy (SICM); Introduction

• remain obscure. A localized ion current flowing through a nanopipette probe represents a suitable non-invasive interaction, which is exploited in scanning ion conductance microscopy (SICM) [19][20][21]. SICM is well suited to probe soft and responsive surfaces, such as those of living cells. The applied

Kondo effects in small-bandgap carbon nanotube quantum dots

• Patryk Florków,
• Damian Krychowski and
• Stanisław Lipiński

Beilstein J. Nanotechnol. 2020, 11, 1873–1890, doi:10.3762/bjnano.11.169

• charging energy. For very weak dot–lead coupling and strong Coulomb interaction, the electrons enter the dot one by one and Coulomb-blockade oscillations of conductance are observed. For stronger coupling to electrodes, higher-order tunneling processes (i.e., cotunneling) begin to play a decisive role

• is correct in the unitary Kondo regime and it leads to a local Fermi-liquid behavior at zero temperature. It gives reliable results of the linear conductance also for systems with weakly broken symmetry. The results obtained are in good agreement with experiments and with renormalization group

• success. The two physical quantities that are the object of our interest are linear conductance and thermoelectric power (TEP) . Both quantities can be determined from the transmissions, which, in turn, can be calculated from the knowledge of Green’s functions obtained in SBMFA or EOM: where fα(E) is