Superconducting spin valve effect in Co/Pb/Co heterostructures with insulating interlayers

• Andrey A. Kamashev,
• Nadir N. Garif’yanov,
• Aidar A. Validov,
• Vladislav Kataev,
• Alexander S. Osin,
• Yakov V. Fominov and
• Ilgiz A. Garifullin

Beilstein J. Nanotechnol. 2024, 15, 457–464, doi:10.3762/bjnano.15.41

• to plot the theoretical curve for (dPb). The value of γ is consistent with the values of ξS and ξF. What is unexpected in the above fitting parameters is a rather small value of the interface resistance parameter, γb = 0.48. In the tunneling limit, one can estimate in terms of the effective

• suppressed). The obtained small value of γb points at small thicknesses of the tunneling barriers in our junctions. Note that this correlates with observations by Deutscher and Meunier [40], who concluded that according to the resistance measurements, the barriers in their experiment were “much thinner than

• in a conventional tunneling junction”. While the theory [50] assumes a symmetric F1/S/F2 structure, our samples may actually be asymmetric from the point of view of the interface transparencies. The oxidation times of the two interfaces were different in our samples, and our fabrication procedure was

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

• Karl Rothe Nicolas Neel Jorg Kroger Institut für Physik, Technische Universität Ilmenau, D-98693 Ilmenau, Germany 10.3762/bjnano.15.37 Abstract Low-energy argon ion bombardment of graphene on Ir(111) induces atomic-scale defects at the surface. Using a scanning tunneling microscope, the two

• ; scanning tunneling microscopy and spectroscopy; Introduction Defects in lattices of two-dimensional (2D) materials are considered as promising building blocks for tailoring electronic and phononic band structures, magnetic texture, photon emission, and charge carrier concentration [1]. In addition

• by noble-gas ion irradiation [6][13][14][17][19][21][24], represents an opportunity for systematic defect studies. The work presented here was stimulated by the lack of experimental data on the actual geometry of atomic-scale defects in graphene. So far, scanning tunneling microscope (STM

On the mechanism of piezoresistance in nanocrystalline graphite

• Sandeep Kumar,
• Simone Dehm and
• Ralph Krupke

Beilstein J. Nanotechnol. 2024, 15, 376–384, doi:10.3762/bjnano.15.34

• values. For larger strains, mechanisms such as grain rotation and the formation of nanocracks might contribute to the piezoresistive behavior in nanocrystalline graphene. Keywords: grain boundary; nanocrystalline graphene; strain sensor; Raman; tunneling and destruction; Introduction Flexible strain

• graphene, it is still unclear which factors influence this property. A theoretical work by Kumar et al. suggested that grain boundaries can affect piezoresistance in graphene [9]. This result seemed unexpected since Dirac particles should undergo Klein tunneling at barriers without adding up to the total

• strain within the grains remains constant even though the externally applied strain increased to ca. 0.4%. In an attempt to model piezoresistance in NCG, we have used the tunneling + destruction model for composite materials [24]: The model with five free parameters was fitted to the data as shown in

Ultrasensitive and ultrastretchable metal crack strain sensor based on helical polydimethylsiloxane

• Shangbi Chen,
• Dewen Liu,
• Weiwei Chen,
• Huajiang Chen,
• Jiawei Li and
• Jinfang Wang

Beilstein J. Nanotechnol. 2024, 15, 270–278, doi:10.3762/bjnano.15.25

• formation under stretching. The sensors with helix indices C1, C2, and C3 exhibited distinct turning points at 250%, 550%, and 850% strain, respectively. The dominance of strain in the sensing mechanism can be attributed to the tunneling effect [37]. As the Au film is stretched, it gradually separates

• , resulting in an increased distance between adjacent cracks. During this stage, the resistance is primarily influenced by the coupling of tunneling resistance with the physical distance between channel cracks. Therefore, the change in resistance, corresponding to the average width of the cracks and the

• strain, can be described by the following formula: When the strain ε is small, we can formulate: where X is the tunneling barrier height-dependent function. Figure 2b shows the good linearity between measured resistance and strain; the curves fit quite well to the analytical solution. When the helical

Design, fabrication, and characterization of kinetic-inductive force sensors for scanning probe applications

• August K. Roos,
• Ermes Scarano,
• Elisabet K. Arvidsson,
• Erik Holmgren and
• David B. Haviland

Beilstein J. Nanotechnol. 2024, 15, 242–255, doi:10.3762/bjnano.15.23

• strip to connect the base of the cone to the Nb-Ti-N film, which is the ground plane of the microwave circuit. This feature enables the measurement of the tunneling current between the tip (grounded) when a DC bias is applied to a conductive sample surface. Scanning tunneling microscopy (STM) operation

Exploring disorder correlations in superconducting systems: spectroscopic insights and matrix element effects

• Vyacheslav D. Neverov,
• Alexander E. Lukyanov,
• Andrey V. Krasavin,
• Alexei Vagov,
• Boris G. Lvov and
• Mihail D. Croitoru

Beilstein J. Nanotechnol. 2024, 15, 199–206, doi:10.3762/bjnano.15.19

• previously reported in [47]. This work focuses on a different aspect of the influence of the disorder correlations, investigating how the latter affect key spectral characteristics of a superconductor, that is, the energy level distribution. Recent scanning tunneling spectroscopy experiments on highly

• to model the s-wave Cooper pairing [51][52], Here, the particle number operators at site i are expressed through the electron operators with spin σ. The tunneling amplitude tij = −t is assumed nonzero only for the nearest sites, μ denotes the chemical potential, Vi is the disorder potential, and g

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

• T → 0 can flow across the junction. The situation becomes entirely different provided one goes beyond the tunneling limit and considers highly transparent superconducting weak links in which case the charge transfer is essentially controlled by the mechanism of multiple Andreev reflection [2]. This

Measurements of dichroic bow-tie antenna arrays with integrated cold-electron bolometers using YBCO oscillators

• Leonid S. Revin,
• Dmitry A. Pimanov,
• Alexander V. Chiginev,
• Anton V. Blagodatkin,
• Viktor O. Zbrozhek,
• Andrey V. Samartsev,
• Anastasia N. Orlova,
• Dmitry V. Masterov,
• Alexey E. Parafin,
• Victoria Yu. Safonova,
• Anna V. Gordeeva,
• Andrey L. Pankratov,
• Leonid S. Kuzmin,
• Anatolie S. Sidorenko,
• Silvia Masi and
• Paolo de Bernardis

Beilstein J. Nanotechnol. 2024, 15, 26–36, doi:10.3762/bjnano.15.3

• system resistance; also, the total noise is decreased. The SN contact should, in turn, accelerate the tunneling of hot electrons from the absorber, serving as an open gate. In the course of measurements of the obtained samples, however, it turned out that the resistance of the obtained samples was higher

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

• current maps after DDT SAM formation. The presence of a well-ordered SAM on the surface was confirmed by scanning tunneling microscopy (STM) images on alkanethiol-covered Au surfaces prepared in the same way, in which the individual molecules can be resolved, shown in Figure S4 in Supporting Information

A bifunctional superconducting cell as flux qubit and neuron

• Dmitrii S. Pashin,
• Pavel V. Pikunov,
• Marina V. Bastrakova,
• Andrey E. Schegolev,
• Nikolay V. Klenov and
• Igor I. Soloviev

Beilstein J. Nanotechnol. 2023, 14, 1116–1126, doi:10.3762/bjnano.14.92

• getting closer, and the anticrossing effect is observed. For the ground and first-excited states, characteristic times of anticrossing correspond to τLZ, when the adiabatic condition (Equation 5) is violated and a non-zero probability of Landau–Zener tunneling between these energy levels emerges. As long

• ,d correspond to regions where there is a non-zero probability of quantum-coherent Landau–Zener tunneling, and black areas correspond to the adiabatic control of the system. According to the expressions in Equation 12, the white dashed line in Figure 2c denotes the limit of the transition probability

• functions [30]. We can see from Figure 2e that for the symmetric control field for given DR,F, there are ranges of inductance values l where we can control the populations of levels by external influence using the Landau–Zener tunneling effect. In other words, in this parameter range we can, if necessary

Two-dimensional molecular networks at the solid/liquid interface and the role of alkyl chains in their building blocks

• Suyi Liu,
• Yasuo Norikane and
• Yoshihiro Kikkawa

Beilstein J. Nanotechnol. 2023, 14, 872–892, doi:10.3762/bjnano.14.72

• and desirable nanoarchitectures. Scanning tunneling microscopy is a powerful tool for revealing the molecular conformations, arrangements, and orientations of two-dimensional (2D) networks on surfaces. The fabrication of 2D assemblies involves non-covalent interactions that play a significant role in

• this review, we focus on the role of alkyl chains in the formation of ordered 2D assemblies at the solid/liquid interface. The alkyl chain effects on the 2D assemblies are introduced together with examples documented in the past decades. Keywords: alkyl chains; scanning tunneling microscopy; self

• coordination, halogen bonding, and dispersion forces [12][13][14][15][16][17][18][19][20][21][22]. Scanning tunneling microscopy (STM) is an important tool for the direct visualization of molecular arrangements, especially for two-dimensional (2D) networks. STM observations have been performed on atomically

Current-induced mechanical torque in chiral molecular rotors

• Richard Korytár and
• Ferdinand Evers

Beilstein J. Nanotechnol. 2023, 14, 711–721, doi:10.3762/bjnano.14.57

• charge carrier and the mass of the helix per winding number. Keywords: molecular junctions; molecular motors; molecular switches; Introduction Experiments employing scanning tunneling microscopy (STM) have achieved the directed rotation of molecules controlled by an electrical current. Correspondingly

• of interest: It implies T → ∞, and, thus, a vanishing threshold Im. Directed motion of a helix with an open end Angular momentum transfer In a scanning tunneling setup, the condition in Equation 2 is not always fulfilled, for example, when the tip of the microscope does not bind to the molecule. In

• of freedom, assuming that the quantization levels of the rotational motion fall below the working temperature. Rotation only happens via inelastic electron tunneling. Importantly, each single electron scattering event must obey fundamental conservation laws. Therefore, the principles outlined in this

Carbon nanotube-cellulose ink for rapid solvent identification

• Tiago Amarante,
• Thiago H. R. Cunha,
• Claudio Laudares,
• Ana P. M. Barboza,
• Ana Carolina dos Santos,
• Cíntia L. Pereira,
• Vinicius Ornelas,
• Bernardo R. A. Neves,
• André S. Ferlauto and
• Rodrigo G. Lacerda

Beilstein J. Nanotechnol. 2023, 14, 535–543, doi:10.3762/bjnano.14.44

• constant of the solvent as shown in Figure 4b. This result suggests that, when the liquid soaks the composite, it swells the material, creating a liquid dielectric barrier between the conductive clusters. Thus, it changes the tunneling process proportionally to the dielectric constant of the liquid. Hence

• pressure of the solvents controls the time the liquid will stay within the sensor before it evaporates. This makes it a key factor regarding the swelling process of the CPC matrix and the electron tunneling process. To investigate this hypothesis, we designed an experiment to mimic the thermal effects

Molecular nanoarchitectonics: unification of nanotechnology and molecular/materials science

• Katsuhiko Ariga

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

• creating a self-assembled monolayer of a diacetylene compound (10,12-nonacosazinoic acid) adsorbed on a graphite surface and biased with a scanning tunneling microscope probe [111]. By positioning the probe at a specific site, the polymerization of the chains was induced within defined small regions, and

• molecules by UV light irradiation. In the process, a cycloaddition reaction occurred between one nearby C60 molecule adsorbed on the surface and the most frontal part of the polydiacetylene molecular skeleton. As a result, nanojunctions were created. Scanning tunneling microscopy proved that the C60

• reversibly terminated by C60 fullerene molecules (Figure 4). First, the Au probe was positioned at the target Br atom site. Then, when the bias voltage was swept, an abrupt change in the tunneling current was detected. As a result, the bromine atoms disappeared from the molecule and the C–Br bonds in the

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

• integrals are taken over the contact areas , and tr(x) denote coordinate- and spin-independent tunneling amplitudes. Let us denote the probability for N1 and N2 electrons to be transferred, respectively, through the junctions 1 and 2 during the observation time t as Pt(N1,N2). Introducing the so-called

• tunneling between the leads, Further analysis of the general expression for the function (Equation 8) is essentially identical to that already carried out in [25]. Therefore, it is not necessary to go into details here. Employing Equation 7 and making use of the results [25], we recover general expressions

• appreciable also at non-zero bias voltages V1,2, in which case it essentially depends on transmission distributions in both junctions. We start from the tunneling limit A1,n, A2,m ≪ 1, where one has Keeping only the terms ∝γ± in the expression (Equation 19), we obtain The first and the second terms on the

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

• of the sample preparation is available in Supporting Information File 1. A qPlus AFM/STM sensor [21] with an etched W-tip was used. Tunneling spectoscopy data (dI/dV data) were acquired with a lock-in amplifier included in the control electronics (Nanonis from SPECS GmbH). The AC signal had a

Induced electric conductivity in organic polymers

• Konstantin Y. Arutyunov,
• Anatoli S. Gurski,
• Vladimir V. Artemov,
• Alexander L. Vasiliev,
• Azat R. Yusupov,
• Danfis D. Karamov and
• Alexei N. Lachinov

Beilstein J. Nanotechnol. 2022, 13, 1551–1557, doi:10.3762/bjnano.13.128

• films can be obtained by centrifugation from a solution in cyclohexanone on a metal surface with a thickness from several nanometers up to micrometers. High homogeneity and defect-free surfaces on nanoscopic scales have been repeatedly confirmed by various methods, including scanning tunneling and

• described in terms of the injection current model limited by the space charge. At low temperatures, the tunneling mechanism is the predominant mechanism. Figure 3 shows the current–voltage characteristics of Pb–PDP–Pb structures with different PDP film thicknesses. With increase of the polymer film

Density of states in the presence of spin-dependent scattering in SF bilayers: a numerical and analytical approach

• Tairzhan Karabassov,
• Valeriia D. Pashkovskaia,
• Nikita A. Parkhomenko,
• Anastasia V. Guravova,
• Elena A. Kazakova,
• Boris G. Lvov,
• Alexander A. Golubov and
• Andrey S. Vasenko

Beilstein J. Nanotechnol. 2022, 13, 1418–1431, doi:10.3762/bjnano.13.117

• superconducting hybrid structures. For example, the DOS calculation is essential for the quasiparticle current computation in SIFS (where I denotes an insulating layer) [29][51][53][54][55][56][57] or SFIFS tunneling Josephson junctions [58]. Therefore, computation of the DOS is also needed for many actively

• description of the corresponding scattering effects on the DOS structure. It should not be forgotten that the linearized solution of the form in Equation 20 is quite limited in its application. In our case, it is valid when γB ≫ 1 and df ≪ min(ξf,), which is true for γB = 50. This tunneling limit is

• features is the examination of the current–voltage characteristics. Utilizing the Werthamer expression for the quasiparticle current in tunneling junctions, we can calculate the I–V curves for an SFIFS junction. The current then reads Here, Nf1,2(E) is the density of states (DOS) in the corresponding

Studies of probe tip materials by atomic force microscopy: a review

• Ke Xu and
• Yuzhe Liu

Beilstein J. Nanotechnol. 2022, 13, 1256–1267, doi:10.3762/bjnano.13.104

• shown to be removed one by one from the sample surface by tip indentation of the scanning tunneling microscope (STM). The probing of the interaction forces by AFM and thus the analysis of van der Waals (vdW) forces can provide valuable information on the evolution of the tip size. Carbon nanotube probes

Design of surface nanostructures for chirality sensing based on quartz crystal microbalance

• Yinglin Ma,
• Xiangyun Xiao and
• Qingmin Ji

Beilstein J. Nanotechnol. 2022, 13, 1201–1219, doi:10.3762/bjnano.13.100

• expose chiral surfaces even with high symmetry and low Miller index surface orientations [131][132][133]. Therefore, metals with chiral surfaces may have enantiospecific interactions with chiral molecules [134][135][136][137][138]. Scanning tunneling microscopy (STM) studies and simulations indicated

A cantilever-based, ultrahigh-vacuum, low-temperature scanning probe instrument for multidimensional scanning force microscopy

• Hao Liu,
• Zuned Ahmed,
• Sasa Vranjkovic,
• Manfred Parschau,
• Andrada-Oana Mandru and
• Hans J. Hug

Beilstein J. Nanotechnol. 2022, 13, 1120–1140, doi:10.3762/bjnano.13.95

• scanning tunneling microscope (STM) can be transformed into a tuning fork-based AFM simply by replacing the rigid STM tip by a tuning fork with an attached tip and by adding an extra pre-amplifier and a PLL to drive the tuning fork oscillation and measure shifts in its resonance frequency arising from the

• . We further demonstrate that this instrument can be used for multimodal AFM operation, for example, to simultaneously map vertical and lateral forces and tunneling current signals with atomic resolution. It also permits the measurement of weak forces with high measurement bandwidths permitting the

• grain boundaries [69] of the rather thick metallic coating applied to the tip side of the cantilever. Note that a nominally 20 nm thick Pt coating is required to permit tunneling, but the coating thickness along the cantilever could presumably be minimized using masking procedures similar to those used

Efficiency of electron cooling in cold-electron bolometers with traps

• Dmitrii A. Pimanov,
• Vladimir A. Frost,
• Anton V. Blagodatkin,
• Anna V. Gordeeva,
• Andrey L. Pankratov and
• Leonid S. Kuzmin

Beilstein J. Nanotechnol. 2022, 13, 896–901, doi:10.3762/bjnano.13.80

• just a refrigerator. One of the possible solutions of the problem is the on-chip electron cooling, which creates a drain of thermal energy from small detecting elements with the help of tunneling electrons. Cold-electron bolometers (CEBs) [1][2][3] have high potential to improve the electron cooling

• , and the coefficient β shows how much of PS comes back to the absorber. PA = IAV is the power due to Andreev heating current, V is the voltage drop across the NIS junction, and Pleak = V2/Rleak is the power associated with the leakage current. The quasi-particle tunneling current is written as: where V

• is the NIS junction voltage, Te and Ts are the electron temperatures in the normal metal and the superconductor, is the density of states in the superconductor, Δ is the superconducting gap, and kB is the Boltzmann constant. Using the integral of the tunneling current through the NIS junction

Numerical modeling of a multi-frequency receiving system based on an array of dipole antennas for LSPE-SWIPE

• Alexander V. Chiginev,
• Anton V. Blagodatkin,
• Dmitrii A. Pimanov,
• Ekaterina A. Matrozova,
• Anna V. Gordeeva,
• Andrey L. Pankratov and
• Leonid S. Kuzmin

Beilstein J. Nanotechnol. 2022, 13, 865–872, doi:10.3762/bjnano.13.77

• help reaching better noise characteristics than those of CEBs with two SIN tunnel junctions due to several reasons. First, the responsivity is increased by a factor of two due to hot electrons tunneling only through one SIN junction. Second, the bolometer resistance is decreased twice, which helps in

Self-assembly of C₆₀ on a ZnTPP/Fe(001)–p(1 × 1)O substrate: observation of a quasi-freestanding C₆₀ monolayer

• Guglielmo Albani,
• Michele Capra,
• Alessandro Lodesani,
• Alberto Calloni,
• Gianlorenzo Bussetti,
• Marco Finazzi,
• Franco Ciccacci,
• Alberto Brambilla,
• Lamberto Duò and
• Andrea Picone

Beilstein J. Nanotechnol. 2022, 13, 857–864, doi:10.3762/bjnano.13.76

• tunneling microscopy/spectroscopy and ultraviolet photoemission spectroscopy. C60 nucleates compact and well-ordered hexagonal domains on top of the ZnTPP buffer layer, suggesting a high surface diffusivity of C60 and a weak coupling between the overlayer and the substrate. Accordingly, work function

• fullerene films stabilized directly on metal surfaces. Our results unveil a model system that could be useful in applications in which a quasi-freestanding monolayer of C60 interfaced with a metallic electrode is required. Keywords: fullerene; scanning tunneling microscopy; ultraviolet photoemission

• W tips. Scanning tunneling spectroscopy (STS) data, that is, dI/dV curves for the investigation of the sample density of states (DOS), have been collected at room temperature, using a lock-in amplifier with a modulation amplitude of 60 mV. All STM and STS measurements have been carried out while

Direct measurement of surface photovoltage by AC bias Kelvin probe force microscopy

• Masato Miyazaki,
• Yasuhiro Sugawara and
• Yan Jun Li

Beilstein J. Nanotechnol. 2022, 13, 712–720, doi:10.3762/bjnano.13.63

• (HF2LI with PID option, Zurich Instruments) to generate and control the AC bias. The typical sensitivity of our measurements was estimated to be δV = 1 mV (see Appendix). We simultaneously measured the tunneling current through the I/V converter as scanning tunneling microscopy (STM) [34] to consider the

• of the rutile TiO2(110) surface. Terrace and step structures were observed, and the surface was flat within a single step height of 325 pm [50]. Figure 3b shows the SPV image obtained simultaneously with the AFM image. No tunneling current was detected in the AC-KPFM measurement. The SPV profile is