Solid-state Stern–Gerlach spin splitter for magnetic field sensing, spintronics, and quantum computing

• Kristofer Björnson and
• Annica M. Black-Schaffer

Beilstein J. Nanotechnol. 2018, 9, 1558–1563, doi:10.3762/bjnano.9.147

• the transfer processes between the leads and the circular edge. We will here assume that this process preserves phase coherence between the states in the leads and the TI edge states, and that it is described by a single tunneling parameter t, which we for now set to t = 1 to indicate perfect

• proportional to the identity matrix and therefore only contribute to the irrelevant α phase. Discussion We would like to end with a few comments on some of the assumptions made when deriving the above results. First of all, the tunneling parameter t, which otherwise would have multiplied the L and R matrices

Spatial Rabi oscillations between Majorana bound states and quantum dots

• Jun-Hui Zheng,
• Dao-Xin Yao and
• Zhi Wang

Beilstein J. Nanotechnol. 2018, 9, 1527–1535, doi:10.3762/bjnano.9.143

• of this amplitude equality by analyzing the spatial Rabi oscillations of the quantum states of a quantum dot that is tunneling-coupled to the Majorana bound states. Results: We find two resonant Rabi driving energies that correspond to the energy splitting due to the coupling of two spatially

• Majorana bound states that have an exponentially protected small splitting energy. As shown in Figure 1a, one of the Majorana bound states is coupled to the quantum dot with a single electron tunneling through a potential barrier. The barrier is produced by a voltage gate, which is implemented between the

• quantum dot and the Majorana island. If an ac voltage is applied to the gate, the tunneling strength between the quantum dot and the Majorana bound states will be driven periodically [39]. We show that there are two resonant driving energies that induce coherent spatial Rabi oscillations between the

Robust topological phase in proximitized core–shell nanowires coupled to multiple superconductors

• Tudor D. Stanescu,
• Anna Sitek and
• Andrei Manolescu

Beilstein J. Nanotechnol. 2018, 9, 1512–1526, doi:10.3762/bjnano.9.142

• produced in a charge transport measurement by tunneling electrons between the semiconductor wire and external electrodes attached to its ends [14][15][16][17][18][19][20][21][22][23][24]. These experiments have provided strong indications regarding the presence of Majorana bound states at the end of the

Electronic conduction during the formation stages of a single-molecule junction

• Atindra Nath Pal,
• Tal Klein,
• Ayelet Vilan and
• Oren Tal

Beilstein J. Nanotechnol. 2018, 9, 1471–1477, doi:10.3762/bjnano.9.138

• scenarios in which a single-molecule junction is formed. Future control over such processes may pave the way for directed formation of preferred junction structures. Keywords: break junction; electron–vibration interactions; electronic transport; inelastic electron tunneling spectroscopy; molecular

• the tunneling transport regime. When vanadocene molecules are introduced, additional conductance plateaus appear below 1 G0, indicating the formation of a metal–molecule–metal junction after the Ag contact is broken. Interestingly, the introduction of molecules into the metal junction also yields new

• histograms taken before and after the introduction of vanadocene molecules. The histogram for bare Ag junctions (blue) shows a conductance peak at ≈1 G0, which is related to single-atom junctions, and a tail at low conductance due to electron tunneling after the junctions are broken. The introduction of

Robust midgap states in band-inverted junctions under electric and magnetic fields

• Álvaro Díaz-Fernández,
• Natalia del Valle and
• Francisco Domínguez-Adame

Beilstein J. Nanotechnol. 2018, 9, 1405–1413, doi:10.3762/bjnano.9.133

• crystalline insulator states in Pb1−xSnxSe [9]. High-resolution scanning tunneling microscopy studies of these topological crystalline insulators provided strong evidence of the coexistence of massless Dirac fermions, protected by crystal symmetry, with massive Dirac fermions consistent with crystal-symmetry

Interplay between pairing and correlations in spin-polarized bound states

• Szczepan Głodzik,
• Aksel Kobiałka,
• Anna Gorczyca-Goraj,
• Andrzej Ptok,
• Grzegorz Górski,
• Maciej M. Maśka and
• Tadeusz Domański

Beilstein J. Nanotechnol. 2018, 9, 1370–1380, doi:10.3762/bjnano.9.129

• ][13][14]. In-gap states (appearing in pairs symmetrically around the Fermi level) can be nowadays controlled electrostatically or magnetically [12] whereas their topography, spatial extent and polarization can be precisely inspected by the state-of-art tunneling measurements [15][16]. It has been

• the Kondo and the leaking Majorana quasiparticle can be confronted with each other. These magnetically polarized YSR and Majorana quasiparticles as well as the subgap Kondo effect can be experimentally verified using tunneling heterostructures with ferromagnetic lead (STM tip). Results and Discussion

• sufficiently long wire (εm = 0) the Kondo effect persists only in the spin-channel ↓, whereas for ↑ electrons there appears a dip in the spectral density at ω = 0. The resulting tunneling conductance is then partly reduced (from the perfect value 2e2/h) to the fractional value 3e2/2h [67][68][71][72][73]. In

Disorder-induced suppression of the zero-bias conductance peak splitting in topological superconducting nanowires

• Jun-Tong Ren,
• Hai-Feng Lü,
• Sha-Sha Ke,
• Yong Guo and
• Huai-Wu Zhang

Beilstein J. Nanotechnol. 2018, 9, 1358–1369, doi:10.3762/bjnano.9.128

• Majorana zero mode, the noise Fano factor approaches zero in the low bias voltage limit due to the resonant Andreev tunneling. However, the Fano factor is finite in the case of a disorder-induced zero-bias peak. Keywords: conductance peak spacing; disorder; Majorana energy splitting; shot noise; zero-bias

• several experiments since 2012 [23][24][25][26][27][28][29][30]. As an important signature of MBSs in the semiconductor nanowires which are proximity-coupled to s-wave superconductors, the zero-bias conductance peak has been observed in the tunneling spectra in the presence of a finite magnetic field [23

• work, three different types of intrinsic disorder in the nanowire are considered: the fluctuations of the site-dependent chemical potential, the nonlinear tunneling between neighboring sites, and the disorder arising in the pairing as a result of inhomogeneous superconductor–semiconductor coupling. In

Andreev spectrum and supercurrents in nanowire-based SNS junctions containing Majorana bound states

• Jorge Cayao,
• Annica M. Black-Schaffer,
• Elsa Prada and
• Ramón Aguado

Beilstein J. Nanotechnol. 2018, 9, 1339–1357, doi:10.3762/bjnano.9.127

• , fault-tolerant quantum computation [4][5][6]. Tunneling into such zero-energy MBSs results in a zero-bias peak of high 2e2/h in the tunnelling conductance in normal–superconductor (NS) junctions due to perfect Andreev reflection into a particle–hole symmetric state [7]. Early tunnelling experiments in

• similar to the effect of temperature discussed above. Notice that in the tunnel regime, τ = 0.6, I() is approximately zero. For the sawtooth profile at = π is preserved and robust when τ is reduced from the fully transparent to the tunnel regime, as seen in Figure 15b. Quite remarkably, in the tunneling

• transmission, i.e., it is preserved even in the tunneling regime. And finally, we showed that reasonable fluctuations in the chemical potential μ (up to 5μ) do not affect the sawtooth profile of I() at = π. Our main contribution are summarized as follows. In short and long SNS junctions of finite length four

Proximity effect in a two-dimensional electron gas coupled to a thin superconducting layer

• Christopher Reeg,
• Daniel Loss and
• Jelena Klinovaja

Beilstein J. Nanotechnol. 2018, 9, 1263–1271, doi:10.3762/bjnano.9.118

• -energy, we find that the induced gap in the presence of only Rashba spin–orbit coupling can be made comparable to the bulk gap of the superconductor only if the tunneling energy scale exceeds the large level spacing of the superconducting layer. As in the 1D case, the large tunneling energy scale induces

• , μs, and Δ the effective mass, chemical potential, and pairing potential of the superconductor, respectively. Local tunneling at the interface between the two materials is assumed to conserve both spin and momentum, where t is the tunneling amplitude. We must take the 2DEG to be located at some finite

• z2D (0 < z2D < d) due to the breakdown of the tunneling Hamiltonian approach for the case where the 2DEG is located at the boundary of the superconductor. The breakdown of the tunneling Hamiltonian results from our neglect of the thickness of the 2DEG (for related calculations in which the finite

Heterostuctures of 4-(chloromethyl)phenyltrichlorosilane and 5,10,15,20-tetra(4-pyridyl)-21H,23H-porphine prepared on Si(111) using particle lithography: Nanoscale characterization of the main steps of nanopatterning

• Phillip C. Chambers and
• Jayne C. Garno

Beilstein J. Nanotechnol. 2018, 9, 1211–1219, doi:10.3762/bjnano.9.112

• studied with scanning tunneling microscopy (STM) to evaluate the surface conformation and molecular geometry [14]. Individual molecules of nonplanar freebase and copper-metallated tetraphenyl porphyrins adsorbed on Cu(111) were investigated using frequency modulated noncontact AFM to resolve subtle

• with a surface orientation defined by the substituents [20]. The self-assembly of manganese meso-tetra(4-pyridyl)porphyrin on Cu(111) was studied using low temperature scanning tunneling microscopy (STM) and atomic force microscopy (AFM) to resolve molecular structures by Chen et al. [21]. A

Circular dichroism of chiral Majorana states

• Javier Osca and
• Llorenç Serra

Beilstein J. Nanotechnol. 2018, 9, 1194–1199, doi:10.3762/bjnano.9.110

• microwave photoassisted tunneling in Majorana nanocircuits have been suggested in [27]. For chiral Majorana states in a 2D square or rectangular geometry the CD at low energies is characterized by a sequence of equally spaced peaks, corresponding to transitions of Bogoliubov–deGennes quasiparticles from

Inverse proximity effect in semiconductor Majorana nanowires

• Alexander A. Kopasov,
• Ivan M. Khaymovich and
• Alexander S. Mel'nikov

Beilstein J. Nanotechnol. 2018, 9, 1184–1193, doi:10.3762/bjnano.9.109

• the reverse process. These rates are determined both by the probability of electron tunneling through the barrier at the superconductor/semiconductor (S/SM) interface and the corresponding densities of states. In particular, it is important that the rate γw is proportional to the DOS in the SM

• the electrons in the subsystems, Δs(r) is the superconducting order parameter, α is the spin–orbit coupling constant, h = gβH/2 is the Zeeman energy, and H is the applied magnetic field. We consider the incoherent tunneling model, which does not conserve the momentum, e.g., due to the presence of the

• disorder at the interface. Thus, the ensemble average of the tunneling amplitudes has the form: where is the length of the order of the atomic scale. The tunneling is also assumed to be independent of energy and spin and occurs locally in time and in space, i.e., from a point r on the superconducting

Combined pulsed laser deposition and non-contact atomic force microscopy system for studies of insulator metal oxide thin films

• Daiki Katsube,
• Hayato Yamashita,
• Satoshi Abo and
• Masayuki Abe

Beilstein J. Nanotechnol. 2018, 9, 686–692, doi:10.3762/bjnano.9.63

• transmission electron microscopy [5][8][9][10][11][12][13]. As atomic resolution methods, scanning probe microscopy including scanning tunneling microscopy (STM) [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] and non-contact atomic force microscopy (NC-AFM) [19][23][29][31][32][33][34

Electron interactions with the heteronuclear carbonyl precursor H₂FeRu₃(CO)₁₃ and comparison with HFeCo₃(CO)₁₂: from fundamental gas phase and surface science studies to focused electron beam induced deposition

• Ragesh Kumar T P,
• Paul Weirich,
• Lukas Hrachowina,
• Marc Hanefeld,
• Ragnar Bjornsson,
• Helgi Rafn Hrodmarsson,
• Sven Barth,
• D. Howard Fairbrother,
• Michael Huth and
• Oddur Ingólfsson

Beilstein J. Nanotechnol. 2018, 9, 555–579, doi:10.3762/bjnano.9.53

Revealing the interference effect of Majorana fermions in a topological Josephson junction

• Jie Liu,
• Tiantian Yu and
• Juntao Song

Beilstein J. Nanotechnol. 2018, 9, 520–529, doi:10.3762/bjnano.9.50

• DOS can be detected by using two STM leads or two normal leads. A single side lead can only detect the Andreev reflection tunneling process in the junction, which cannot reveal information about the interference effect in general. However, using two side leads, we can reveal information about the

• experimentally is related to ferromagnetic atomic chains, which are put on a trivial superconductor [15]. It is believed that MFs can generate a zero-bias conductance peak (ZBP) in the conductance spectrum [16][17][18][19], and indeed the signature of ZBPs has been observed in both systems in tunneling

• show that a single side lead can only detect the Andreev reflection tunneling process in the junction, which cannot reveal information about the interference effect in general. However, using the two side leads, we can display information about the interference effect of the MFs by combining Andreev

Transition from silicene monolayer to thin Si films on Ag(111): comparison between experimental data and Monte Carlo simulation

• Alberto Curcella,
• Romain Bernard,
• Yves Borensztein,
• Silvia Pandolfi and
• Geoffroy Prévot

Beilstein J. Nanotechnol. 2018, 9, 48–56, doi:10.3762/bjnano.9.7

• Alberto Curcella Romain Bernard Yves Borensztein Silvia Pandolfi Geoffroy Prevot Sorbonne Universités, UPMC Univ Paris 06, CNRS-UMR 7588, Institut des NanoSciences de Paris, F-75005, Paris, France 10.3762/bjnano.9.7 Abstract Scanning tunneling microscopy (STM), Auger electron spectroscopy (AES

• spectroscopy; scanning tunneling microscopy; silicene; silicon; silver; Introduction Since their discovery in 2012 [1], silicene layers have been attracting a great interest, due to the expectation of electronic properties similar to the ones of graphene, based on theoretical studies [2]. Because of their

• ], ARPES [31] and grazing incidence X-ray diffraction [32]. The diamond-like structure of the film has been confirmed by scanning tunneling microscopy (STM) [33] and optical measurements [34]. The Ag termination of the surface has been also demonstrated by Auger electron spectroscopy (AES) [34], metastable

The role of ligands in coinage-metal nanoparticles for electronics

• Ioannis Kanelidis and
• Tobias Kraus

Beilstein J. Nanotechnol. 2017, 8, 2625–2639, doi:10.3762/bjnano.8.263

• ligands [52]. Typical conduction mechanisms within such films are tunneling or electron hopping [26][53]. An exponential dependence of the tunneling-dominated film conductivity on the number of saturated carbon–carbon bonds in the ligands has been reported [54][55]. The chemical nature of dithiols or

• allowed the electron wave functions between neighboring nanoparticles to overlap and electron transport was described by thermally activated tunneling between the particles. Locating the Fermi level of the metal in the HOMO–LUMO gap of the ligand shell provides a pathway for electrons to pass along [56

• created by the surrounding dielectric ligand shell of nanoparticles. Depending on the thickness of the barrier, electron transport has been described as quantum tunneling, electron hopping, ohmic conduction, or space-charge-limited conduction, to mention only a few [53][57][109][110]. Several reports

Inelastic electron tunneling spectroscopy of difurylethene-based photochromic single-molecule junctions

• Youngsang Kim,
• Safa G. Bahoosh,
• Dmytro Sysoiev,
• Thomas Huhn,
• Fabian Pauly and
• Elke Scheer

Beilstein J. Nanotechnol. 2017, 8, 2606–2614, doi:10.3762/bjnano.8.261

• theoretical analysis of charge transport through diarylethene-derived single-molecule devices, which are created using the mechanically controlled break-junction technique. Inelastic electron tunneling (IET) spectroscopy measurements performed at 4.2 K are compared with first-principles calculations in the

• : inelastic electron tunneling spectroscopy; molecular junction; photochromic; single molecule; Introduction Molecular junctions hold promise for the realization of novel miniaturized electronic circuits [1][2][3][4][5][6] as well as for thermoelectric energy conversion devices [7][8][9][10]. Optoelectronic

• C5F-ThM molecules [14]. The overall magnitude of the conductance of both the open and the closed form is rather small. This can be attributed to the presence of sp3 hybridized methylene groups, isolating the π-system and the thiol anchor groups. These act as efficient tunneling barriers for the

Towards molecular spintronics

• Georgeta Salvan and
• Dietrich R. T. Zahn

Beilstein J. Nanotechnol. 2017, 8, 2464–2466, doi:10.3762/bjnano.8.245

• molecules; (magneto-)optical spectroscopy; molecular spintronics; photoelectron spectroscopy; surface science; thin films; The discovery of tunneling and giant magnetoresistance in inorganic spin valves has led to a revolution in the field of magnetic memory and the significant increase in the storage

Comparing postdeposition reactions of electrons and radicals with Pt nanostructures created by focused electron beam induced deposition

• Julie A. Spencer,
• Michael Barclay,
• Miranda J. Gallagher,
• Robert Winkler,
• Ilyas Unlu,
• Yung-Chien Wu,
• Harald Plank,
• Lisa McElwee-White and
• D. Howard Fairbrother

Beilstein J. Nanotechnol. 2017, 8, 2410–2424, doi:10.3762/bjnano.8.240

• indicate that exposure of the PtCl2 deposits to AH and the resulting purification can also lead to significant Pt atom mobility. We believe that the mobility of Pt atoms can be rationalized in the context of scanning tunneling microscopy observations made by Horch et al., who found that the diffusion of

Robust procedure for creating and characterizing the atomic structure of scanning tunneling microscope tips

• Sumit Tewari,
• Koen M. Bastiaans,
• Milan P. Allan and
• Jan M. van Ruitenbeek

Beilstein J. Nanotechnol. 2017, 8, 2389–2395, doi:10.3762/bjnano.8.238

• Sumit Tewari Koen M. Bastiaans Milan P. Allan Jan M. van Ruitenbeek Huygens–Kamerlingh Onnes Laboratory, Leiden University, Niels Bohrweg 2, 2333 CA Leiden, Netherlands 10.3762/bjnano.8.238 Abstract Scanning tunneling microscopes (STM) are used extensively for studying and manipulating matter at

• to the second atomic layer. We demonstrate a controlled evolution of such tips starting from undefined tip shapes. Keywords: adatom imaging; mechanical annealing; scanning tunneling microscopy (STM); STM tip; tip apex; Introduction After the advent of the scanning tunneling microscope (STM) in 1981

• [1][2], it became possible to image conducting surfaces with atomic resolution. STM operates by bringing the apex of a fine metallic wire into tunneling distance from a surface of interest. By providing feedback in the tunnel current and scanning the tip over the surface one can make topographic maps

Surfactant-induced enhancement of droplet adhesion in superhydrophobic soybean (Glycine max L.) leaves

• Oliver Hagedorn,
• Ingo Fleute-Schlachter,
• Hans Georg Mainx,
• Viktoria Zeisler-Diehl and
• Kerstin Koch

Beilstein J. Nanotechnol. 2017, 8, 2345–2356, doi:10.3762/bjnano.8.234

• crystal structure and scanning tunneling microscope (STM) analysis by Koch et al. [46] showed that polar groups of the primary alcohols are introverted and the nonpolar proportion is orientated to the outside of the platelet-shaped wax crystals. According to our results, it is concluded that surfactants

Ester formation at the liquid–solid interface

• Nguyen T. N. Ha,
• Thiruvancheril G. Gopakumar,
• Nguyen D. C. Yen,
• Carola Mende,
• Lars Smykalla,
• Maik Schlesinger,
• Roy Buschbeck,
• Tobias Rüffer,
• Heinrich Lang,
• Michael Mehring and
• Michael Hietschold

Beilstein J. Nanotechnol. 2017, 8, 2139–2150, doi:10.3762/bjnano.8.213

• /bjnano.8.213 Abstract A chemical reaction (esterification) within a molecular monolayer at the liquid–solid interface without any catalyst was studied using ambient scanning tunneling microscopy. The monolayer consisted of a regular array of two species, an organic acid (trimesic acid) and an alcohol

• supported. Keywords: on-surface reaction; scanning tunneling microscopy; trimesic acid; undecan-1-ol; Introduction On-surface reactions are a widespread class of chemical reactions taking place on a surface or at an interface involving active participation of two-dimensional molecular entities. This

• participation is usually beyond the role of just being a solid support for the reactants. Using scanning tunneling microscopy (STM) it is possible to actively study the elementary processes of on-surface reactions. Different types of reactions such as Ullmann coupling, imine coupling, boronic anhydridation

Electronic structure, transport, and collective effects in molecular layered systems

• Torsten Hahn,
• Tim Ludwig,
• Carsten Timm and
• Jens Kortus

Beilstein J. Nanotechnol. 2017, 8, 2094–2105, doi:10.3762/bjnano.8.209

• is the fact that the TMR changes sign depending on the applied bias voltage, which demonstrates the effect of the molecular properties on the observed current and ultimately on the TMR effect. It was already validated experimentally in [30] that the tunneling through single CoPc molecules on

• if the energies are reasonable, the magnitude of the tunneling currents through nanoscale devices are often strongly overestimated [32][33][34][35]. The origins of these problems are threefold: First, tunneling under a finite bias is a non-equilibrium situation that is not well described by standard

• -correlation functionals for transport calculations [38] and by the high computational cost. Second, standard functionals for DFT do not describe strongly correlated systems particularly well. Third, NEGFs can describe tunneling (hybridization) exactly but naturally lead to perturbative approximations for

High-stress study of bioinspired multifunctional PEDOT:PSS/nanoclay nanocomposites using AFM, SEM and numerical simulation

• Alfredo J. Diaz,
• Hanaul Noh,
• Tobias Meier and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2017, 8, 2069–2082, doi:10.3762/bjnano.8.207

• ]. In the case of PEDOT, the perimeter is taken to be 0.774 nm [70]. Using the multibarrier tunneling model in conjunction with the PFEO, we can now calculate the transmission probability for the electrons corresponding to the PFEO energy levels, for different numbers of barriers (N) and for different

• is not uniform, presumably due to the existence of a variety of alternate electron paths, where tunneling is not always the dominant mechanism. Clearly, the brick and mortar structure is not perfect and the concentration and distribution of platelets varies throughout and across the film, as shown by