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

• 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

Nonequilibrium Kondo effect in a graphene-coupled quantum dot in the presence of a magnetic field

• Levente Máthé and
• Ioan Grosu

Beilstein J. Nanotechnol. 2020, 11, 225–239, doi:10.3762/bjnano.11.17

• interacting QD connected to electrodes of massless Dirac fermions in the zero-bias voltage limit [36][37]. The zero-bias conductance plots reveal an impurity quantum phase transition between the Kondo and local moment regimes. Furthermore, the thermopower changes its sign when the temperature approaches the

Transport signatures of an Andreev molecule in a quantum dot–superconductor–quantum dot setup

• Zoltán Scherübl,
• András Pályi and
• Szabolcs Csonka

Beilstein J. Nanotechnol. 2019, 10, 363–378, doi:10.3762/bjnano.10.36

• , which allow one to identify and quantify the dominant non-local term. In particular, we describe the ground-state properties (phase diagram, average electron occupation) of the system, the zero-bias conductance describing electron transport through the device in the presence of tunnel-coupled normal

• . Finally, we analyze the transport signatures of the different non-local coupling terms via the zero bias conductance, the finite-bias conductance, and the triplet blockade effect. Model Microscopic Hamiltonian of the proximitized double quantum dot Throughout this work, we study a standard Cooper-pair

• effectively tune the ratio of these parameters. The left column of Figure 2 shows the phase diagram, the middle column shows the zero-bias conductance of QDL, and the right column shows the average electron occupation of QDL for different ΓCAR, γEC and tLR values. Note that for all cases the local pairing

Interaction-induced zero-energy pinning and quantum dot formation in Majorana nanowires

• Samuel D. Escribano,
• Alfredo Levy Yeyati and
• Elsa Prada

Beilstein J. Nanotechnol. 2018, 9, 2171–2180, doi:10.3762/bjnano.9.203

• through the proximitized nanowire, which has been addressed in several experiments [10][12][13][14][15][16][17][18][19]. In a long wire (the length of which is much greater than the induced coherence length) the presence of MBSs manifests itself in the appearance of a zero-bias conductance peak the width

• that deviate from zero energy, leading to an oscillatory pattern in the low-bias conductance as a function of Zeeman field, chemical potential or wire length [21][22][23]. Conspicuously, in most of the available experimental data the emergence of a robust zero-bias conductance peak is observed above

• MBSs to zero energy around parity crossings and, thus, to more robust zero-bias conductance peaks than predicted by the non-interacting models. The aim of the present work is to test the validity of the predictions of [33] for the case of more realistic calculations of the induced electrostatic

Electromigrated electrical optical antennas for transducing electrons and photons at the nanoscale

• Arindam Dasgupta,
• Mickaël Buret,
• Nicolas Cazier,
• Marie-Maxime Mennemanteuil,
• Reinaldo Chacon,
• Kamal Hammani,
• Jean-Claude Weeber,
• Juan Arocas,
• Laurent Markey,
• Gérard Colas des Francs,
• Alexander Uskov,
• Igor Smetanin and
• Alexandre Bouhelier

Beilstein J. Nanotechnol. 2018, 9, 1964–1976, doi:10.3762/bjnano.9.187

• , differently [42] leading to asymmetric output characteristics. Electron tunneling through an asymmetrical trapezoidal barrier is described following Brinkman’s formalism [43]: with and . is the zero-bias conductance: d is here in angstroms, A is in square nanometers, e is in coulombs and is in

• emitted by inelastic tunneling because the detected spectral range is below the bias energy: hν < eVdc. The zero-bias conductance values are all about 10−2G0. In the set of images in Figure 6, the strongest signal detected through the glass slide originates from the junction itself. However, the images

• also on the barrier width. We show that upon injection of electrons, the electromigrated tunnel junctions are emitting light. The emission mechanism depends on the zero-bias conductance G of the tunnel junction. Roughly speaking, light is generated by inelastic tunneling events when G is much smaller

Josephson effect in junctions of conventional and topological superconductors

• Alex Zazunov,
• Albert Iks,
• Miguel Alvarado,
• Alfredo Levy Yeyati and
• Reinhold Egger

Beilstein J. Nanotechnol. 2018, 9, 1659–1676, doi:10.3762/bjnano.9.158

• ][5][6][7][8][9][10][11][12], and they may also be designed in two-dimensional layouts by means of gate lithography techniques. Over the last few years, several experiments employing such platforms have provided mounting evidence for MBSs, e.g., from zero-bias conductance peaks in N–TS junctions

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

• candidate is the hybrid system of a spin–orbit-coupling nanowire and a conventional superconductor. Robust zero-bias conductance peak was first reported in this system, which originates from the self-conjugate nature of Majorana bound states and therefore was wildly recognized as a signature. An exotic

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

• topological character of these modes endows them with robustness against perturbations that do not close the superconductor gap, e.g., weak interactions, wire bending, a certain amount of disorder, etc. The most straightforward experimental signature of a Majorana mode is a zero-bias conductance peak that is

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

• 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

• zero-bias conductance peak in presence of disorder. We adopt the non-equilibrium Green’s function (NEGF) method for a tight-binding model of the nanowire. Three different types of disorder are separately considered, including the disorder in the site-dependent chemical potential, the spatial

• conductance peak spacings and reformation of the zero-bias peak, which we discuss below, is independent of Coulomb blockade physics. In the presence of a charging energy in the nanowire, it was shown that the zero-bias conductance values are considerably suppressed by the Coulomb energy [75]. The situation of

Circular dichroism of chiral Majorana states

• Javier Osca and
• Llorenç Serra

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

• states in condensed matter devices is attracting strong interest for a few years now [1][2][3][4][5][6][7][8]. The measured zero-bias conductance peaks in hybrid semiconductor/superconductor nanowires have been attributed to the presence of localized Majorana modes on the two ends of the nanowires [9][10

• ][11][12][13][14]. A Majorana mode enhances the zero-bias conductance by allowing a perfect Andreev backscattering at zero excitation energy when the nanowire is attached to a normal lead. These peculiar pairs of states may be seen as nonlocal split fermions, protected by an energy gap that separates

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

• 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

Invariance of molecular charge transport upon changes of extended molecule size and several related issues

• Ioan Bâldea

Beilstein J. Nanotechnol. 2016, 7, 418–431, doi:10.3762/bjnano.7.37

• energy (zero-bias conductance) computed within the WBL coincides with the exact transmission. Therefore, provided that GC,0 is computed exactly, otherwise This is a general result that applies to any exact treatment of uncorrelated transport based on the trace formula of Equation 5. Two WBL schemes have

Can molecular projected density of states (PDOS) be systematically used in electronic conductance analysis?

• Tonatiuh Rangel,
• Gian-Marco Rignanese and
• Valerio Olevano

Beilstein J. Nanotechnol. 2015, 6, 1247–1259, doi:10.3762/bjnano.6.128

• such junctions (including the measurement of their current–voltage characteristics) is, however, still difficult to achieve. In order to obtain a reliable single-molecule zero-bias conductance, it was suggested to resort to a statistically significant sample of tens of thousands of measurements [4

• ]. From this breakthrough work, it is now possible to quote the zero-bias conductance of some molecular junctions such as benzene-diamine (BDA) and benzene-dithiol (BDT) between gold leads. Nevertheless, important characterization uncertainties still persist. For instance, in these experiments, the

• of the zero-bias conductance. A very common approach for providing such an interpretation proceeds as follows. A set of molecular orbitals (MOs) associated to the central molecule are identified and classified according to the energy levels (e.g., the highest occupied molecular orbital (HOMO), or the

Current–voltage characteristics of single-molecule diarylethene junctions measured with adjustable gold electrodes in solution

• Bernd M. Briechle,
• Youngsang Kim,
• Philipp Ehrenreich,
• Artur Erbe,
• Dmytro Sysoiev,
• Thomas Huhn,
• Ulrich Groth and
• Elke Scheer

Beilstein J. Nanotechnol. 2012, 3, 798–808, doi:10.3762/bjnano.3.89

• , or just instable contacts due to unspecific binding. This interpretation is supported by the further analysis of the conductance (transmission) histograms. As an example we plot in Figure 3 the conductance histograms calculated from the zero-bias conductance over all I–V’s recorded on the species TSC

P-wave Cooper pair splitting

• Henning Soller and
• Andreas Komnik

Beilstein J. Nanotechnol. 2012, 3, 493–500, doi:10.3762/bjnano.3.56

• ]. Results and Discussion Superconductor–ferromagnet beam splitters Splitting of spin-polarized p-wave Cooper pairs can easily be identified in the conductance. From the result in [27] we find the generalization of Beenakker’s formula [34] for the zero-bias conductance of a beam splitter realized by a

• Andreev reflection (SAR) induces triplet correlations in the ferromagnet [29]. To see whether similar effects occur in our setup we calculate the zero-bias conductance analogously to Equation 1 for the case of P1 = P2 = 1, meaning maximal parallel polarization and again refer to the tunnel rates for

Towards quantitative accuracy in first-principles transport calculations: The GW method applied to alkane/gold junctions

• Mikkel Strange and
• Kristian S. Thygesen

Beilstein J. Nanotechnol. 2011, 2, 746–754, doi:10.3762/bjnano.2.82

• electronic structure of the Au tips. The zero-bias conductance is obtained from the transmission function at the Fermi level, G = G0T(EF) where G0 = 2e2/h is the unit of quantum conductance. The zero-bias conductance is plotted in Figure 6 as a function of the molecular length. We have also included the DFT

Charge transport in a zinc–porphyrin single-molecule junction

• Mickael L. Perrin,
• Christian A. Martin,
• Ferry Prins,
• Ahson J. Shaikh,
• Rienk Eelkema,
• Jan H. van Esch,
• Jan M. van Ruitenbeek,
• Herre S. J. van der Zant and
• Diana Dulić

Beilstein J. Nanotechnol. 2011, 2, 714–719, doi:10.3762/bjnano.2.77

• stability increases, and both the thermal noise and thermal broadening decrease. We therefore cooled down the junctions to cryogenic temperature (6 K) while keeping the zero-bias conductance at a fixed value (around 1∙10−4 G0) with a feedback loop. In Figure 3a and Figure 3b, we present low-temperature I(V

Interaction of spin and vibrations in transport through single-molecule magnets

• Falk May,
• Maarten R. Wegewijs and
• Walter Hofstetter

Beilstein J. Nanotechnol. 2011, 2, 693–698, doi:10.3762/bjnano.2.75

• effects are distinguishable, especially for SMM with large spin. Finally, we remark that for an SMM with integer spin S, there is no QST-Kondo effect at zero field, but instead a zero-bias conductance dip (for 0 < E < D). As pointed out in [24] a transverse magnetic field results in a QST-Kondo effect