Anomalous current–voltage characteristics of SFIFS Josephson junctions with weak ferromagnetic interlayers

• Tairzhan Karabassov,
• Anastasia V. Guravova,
• Aleksei Yu. Kuzin,
• Elena A. Kazakova,
• Shiro Kawabata,
• Boris G. Lvov and
• Andrey S. Vasenko

Beilstein J. Nanotechnol. 2020, 11, 252–262, doi:10.3762/bjnano.11.19

• interlayers, which we attribute to DOS energy dependencies in the case of small exchange fields in the F layers. Keywords: current–voltage characteristics; Josephson junctions; proximity effect, superconductivity; superconductor/ferromagnet hybrid nanostructures; Introduction It is well known that

• superconductivity and ferromagnetism are two competing antagonistic orders. In superconductors (S) electrons form Cooper pairs with opposite spins and momenta, while in ferromagnetic metals (F) electron spins tend to align in parallel. Nevertheless, it is possible to combine S and F layers in one hybrid structure

• of the S layer and is the superconducting coherence length. The parameter γ defines the strength of the inverse proximity effect, i.e., the suppression of superconductivity in the adjacent S layer by the ferromagnetic layer F. We consider the parameter γ to be relatively small γ ≪ 1, which

Porous silver-coated pNIPAM-co-AAc hydrogel nanocapsules

• William W. Bryan,
• Riddhiman Medhi,
• Maria D. Marquez,
• Supparesk Rittikulsittichai,
• Michael Tran and
• T. Randall Lee

Beilstein J. Nanotechnol. 2019, 10, 1973–1982, doi:10.3762/bjnano.10.194

• William W. Bryan Riddhiman Medhi Maria D. Marquez Supparesk Rittikulsittichai Michael Tran T. Randall Lee Department of Chemistry and the Texas Center for Superconductivity, University of Houston, 4800 Calhoun Road, Houston, TX 77204-5003, United States 10.3762/bjnano.10.194 Abstract This paper

• Center for Superconductivity for supporting this research.

First principles modeling of pure black phosphorus devices under pressure

• Ximing Rong,
• Zhizhou Yu,
• Zewen Wu,
• Junjun Li,
• Bin Wang and
• Yin Wang

Beilstein J. Nanotechnol. 2019, 10, 1943–1951, doi:10.3762/bjnano.10.190

• electronic properties [3][4][5][6], optical spectra [7][8][9][10], excitons [11][12][13], quantum transport [14][15][16][17][18], plasmons [5][19], thermoelectric effects [20][21], and superconductivity [22][23][24] of BP. One of the most promising applications of BP at the industrial level is expected to be

Remarkable electronic and optical anisotropy of layered 1T’-WTe₂ 2D materials

• Qiankun Zhang,
• Rongjie Zhang,
• Jiancui Chen,
• Wanfu Shen,
• Chunhua An,
• Xiaodong Hu,
• Mingli Dong,
• Jing Liu and
• Lianqing Zhu

Beilstein J. Nanotechnol. 2019, 10, 1745–1753, doi:10.3762/bjnano.10.170

• for the type-II Weyl semimetal [18] and quantum spin Hall insulator material [19]. Additionally, many other remarkable properties of WTe2 have also been revealed, such as the temperature-driven Lifshitz transition [20], pressure-induced superconductivity [21], linear Nernst response [22], etc

Kelvin probe force microscopy work function characterization of transition metal oxide crystals under ongoing reduction and oxidation

• Dominik Wrana,
• Karol Cieślik,
• Wojciech Belza,
• Christian Rodenbücher,
• Krzysztof Szot and
• Franciszek Krok

Beilstein J. Nanotechnol. 2019, 10, 1596–1607, doi:10.3762/bjnano.10.155

• nanostructures exhibit a strong absorbance of light over a broad spectrum, which is of potential use in novel tumor therapy [19]. In addition, in the previous year, a profound interest was focused on the superconductivity of various TiO structures [20][21]. According to those, rock-salt TiO is a type-II

• superconductor with a superconductivity transition temperature (Tc) of 5.5 K, which is higher than previously reported results [22]. As a result of its electronic structure, titanium monoxide nanoparticles find further application in heterogeneous catalysis, e.g., for the hydrogenation of styrene [1]. Here we

Superconducting switching due to a triplet component in the Pb/Cu/Ni/Cu/Co₂Cr_1−xFe_xAl_y spin-valve structure

• Andrey Andreevich Kamashev,
• Nadir Nurgayazovich Garif’yanov,
• Aidar Azatovich Validov,
• Joachim Schumann,
• Vladislav Kataev,
• Bernd Büchner,
• Yakov Victorovich Fominov and
• Ilgiz Abdulsamatovich Garifullin

Beilstein J. Nanotechnol. 2019, 10, 1458–1463, doi:10.3762/bjnano.10.144

• dPb = 105 nm. Moreover, this procedure is standard for a simple estimation of the boundary parameters. In particular, it enables to determine the critical thickness of the SC layer below which superconductivity vanishes . From this we obtain, in accordance with the Appendix in [22], the transparency

Energy distribution in an ensemble of nanoparticles and its consequences

• Dieter Vollath

Beilstein J. Nanotechnol. 2019, 10, 1452–1457, doi:10.3762/bjnano.10.143

• , it was also applied to calculate particle size distributions from experimental data of phase transformations. As examples, the superparamagnetic transition of cobalt particles and the transition of lead particles from normal conductance to superconductivity were applied. Within the precision of the

Synthesis and characterization of quaternary La(Sr)S–TaS₂ misfit-layered nanotubes

• Marco Serra,
• Erumpukuthickal Ashokkumar Anumol,
• Dalit Stolovas,
• Iddo Pinkas,
• Ernesto Joselevich,
• Reshef Tenne,
• Andrey Enyashin and
• Francis Leonard Deepak

Beilstein J. Nanotechnol. 2019, 10, 1112–1124, doi:10.3762/bjnano.10.111

• resonators [11][12][13]. Using ionic liquid gating, ambipolar p–n junctions led to high-performance light-emitting diodes (LEDs) and photovoltaic devices [14]. Most interesting, however, was the demonstration of quasi-1D superconductivity, which reflected the non-centrosymmetric structure of the chiral WS2

Periodic Co/Nb pseudo spin valve for cryogenic memory

• Nikolay Klenov,
• Yury Khaydukov,
• Sergey Bakurskiy,
• Roman Morari,
• Igor Soloviev,
• Vladimir Boian,
• Thomas Keller,
• Mikhail Kupriyanov,
• Anatoli Sidorenko and
• Bernhard Keimer

Beilstein J. Nanotechnol. 2019, 10, 833–839, doi:10.3762/bjnano.10.83

• function for the solution of Equation 1, Equation 2 and Equation 3. As it follows from Figure 1 the existence of intrinsic superconductivity of the spacer significantly increases IC of the S/F/s/F/S compared to the S/F/N/F/S junction. The effect can be essentially enhanced in S/[F/s]n/F/S Josephson devices

• , we have generalized the S/[F/N]n model [25] to the case of the existence of intrinsic superconductivity in its non-ferromagnetic parts. To make the model more realistic we consider a case of a periodic pseudo-spin-valve structure, where two neighboring F layers have slightly different thicknesses d1

• proposed S/[F1/s/F2/s]n/F1/S Josephson devices requires the development of a technology for manufacturing of multilayer structures that satisfy the following conditions: (a) presence of superconductivity in the s layers with TC 4.2 K, (b) in plane orientation of the magnetization vector in the F films

Surface energy of nanoparticles – influence of particle size and structure

• Dieter Vollath,
• Franz Dieter Fischer and
• David Holec

Beilstein J. Nanotechnol. 2018, 9, 2265–2276, doi:10.3762/bjnano.9.211

• Fermi–Dirac statistics (e.g., melting, ferromagnetism, diffusion, etc.) and s = 1 for properties related to quasi-particles following the Bose–Einstein statistics (e.g., superconductivity or vibration) [30][31][32]. Karasevskii [33] started with a different approach based on size dependent quantization

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

• , such as InAs or InSb, are becoming ideal systems for the artificial generation of topological superconductivity [1][2][3]. In addition to its fundamental interest, such nanowires that may host Majorana bound states (MBSs) at their ends or interfaces [4][5] constitute promising platforms for Majorana

Increasing the performance of a superconducting spin valve using a Heusler alloy

• Andrey A. Kamashev,
• Aidar A. Validov,
• Joachim Schumann,
• Vladislav Kataev,
• Bernd Büchner,
• Yakov V. Fominov and
• Ilgiz A. Garifullin

Beilstein J. Nanotechnol. 2018, 9, 1764–1769, doi:10.3762/bjnano.9.167

• of the S layer, , which is defined as the thickness below which there is no superconductivity in the S/F bilayer: . In the limiting case , the thickness can be calculated explicitly as [29] Here γE ≈ 1.78 is the Euler constant. Our data yield (γb = 1.95) for the Fe/In system, (γb = 2.7) for the Fe

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

• -terminal S–TS–S geometry, where the TS wire acts as tunable parity switch on the Andreev bound states in a superconducting atomic contact. Keywords: Andreev bound states; Josephson current–phase relation; Majorana zero modes; topological superconductivity; Introduction The physics of topological

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

• system in the presence of non-vanishing transverse potentials and finite relative phases between the parent superconductors. We show that having finite relative phases strongly enhances the stability of the induced topological superconductivity over a significant range of chemical potentials and reduces

• sign change of the Pfaffian, is accompanied by the closing of the quasiparticle gap at k = 0. Results and Discussion Nanowire coupled to superconductors with no relative phase difference The emergence of topological superconductivity and zero-energy Majorana bound states in core–shell nanowires coupled

• superconductivity (and the corresponding Majorana modes) are not very robust. An important difference between the phase diagram shown in Figure 5 and that in Figure 2 is that for the square wire we have used a larger value of the inter-chain hopping, t′ = 2.25 meV. Enhancing the coupling between chains widens the

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

• near to the singlet–doublet phase transition. Keywords: bound states in superconductors; Majorana quasiparticles; subgap Kondo effect; Introduction Magnetism is usually detrimental to superconductivity because it breaks the Cooper pairs (at the critical field strength Hc2). There are, however, a few

• exceptions in which these phenomena coexist, e.g., in iron pnictides [1], CeCoIn5 [2]. Also, sometimes magnetic fields induce superconductivity [3]. Plenty of other interesting examples can be found in nanoscopic systems, where magnetic impurities (dots) exhibit a more subtle relationship with the electron

• unit vector shows the direction of the spin–orbit field, which can be arbitrary. Here we restrict our considerations to the in-plane = (1, 0, 0) polarization, which will be important for nontrivial superconductivity in nanowires discussed in the subsection ’Magnetically polarized Majorana

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

• with SOC, where we show that only the right combination of Rashba SOC, a Zeeman field perpendicular to the spin–orbit axis and s-wave superconductivity leads to the emergence of MBSs. Similar results have been presented elsewhere but we include them here for the sake of readability of the next sections

• length LN, as shown in Figure 3. The regions N and SL(R) are described by the tight-binding Hamiltonian H0 given by Equation 4 with their respective chemical potentials, μN and . The Hamiltonian describing the SNS junction without superconductivity is then given by where with i = L/R and HN are the

• also valid for long junctions. The superconducting regions of the nanowire are characterized by chemical potential and the uniform superconducting pairing potentials [52][53] and , where Δ < ΔS′ and . The central region of the nanowire is in the normal state without superconductivity, ΔN = 0, and

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

• Christopher Reeg Daniel Loss Jelena Klinovaja Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland 10.3762/bjnano.9.118 Abstract There have recently been several experiments studying induced superconductivity in semiconducting two-dimensional electron

• . Keywords: Majorana fermions; mesoscopic physics; proximity effect; quantum computing; topological superconductivity; Introduction Topological superconductors host zero-energy Majorana bound states at their edges that are highly sought for applications in topological quantum computing [1][2][3]. The two

• proposals to realize topological superconductivity that have received the most attention to date involve engineering Majorana bound states in either low-dimensional semiconducting systems [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] or in ferromagnetic atomic chains [24][25][26

Circular dichroism of chiral Majorana states

• Javier Osca and
• Llorenç Serra

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

• decays exponentially with the distance to the nanowire end. By contrast, propagating Majorana states with sustained spatial oscillations can be present at the edges and along the perimeter of 2D-like hybrid structures. This is the situation in presence of p + ip superconductivity for spinless

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

• Novgorod, 23 Gagarina, 603950 Nizhny Novgorod, Russia 10.3762/bjnano.9.109 Abstract We study the influence of the inverse proximity effect on the superconductivity nucleation in hybrid structures consisting of semiconducting nanowires placed in contact with a thin superconducting film and discuss the

• correlations in the low-field domain and for the reentrant superconductivity at high magnetic fields in the topologically nontrivial regime. The growth of the critical temperature in the latter case continues up to the upper critical field destroying the pairing inside the superconducting film due to either

• superconductivity, is known to possess still a number of important shortcomings. An obvious way to overcome these shortcomings is to use the microscopic theory of the proximity effect [17][18][19][20][21][22][23][24], i.e., Gor'kov equations. The microscopic approach allows one to get the effective gap operator

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

• deposition; Introduction The surfaces of metal oxides have attractive and useful properties, such as superconductivity, ferroelectricity and catalytic activity [1]. These properties are derived from the unique structure, the electron and spin interactions, the degree of freedom of the electron orbit and the

• grown on substrate materials have been studied for correlated electron heterostructures and devices. One of the most important and common uses of epitaxial LaAlO3 is its interface with SrTiO3 for studies of electrical conductivity [4], superconductivity [59], photoconductivity [60], and

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

• with Rashba spin–orbit coupling and proximity-induced superconductivity appear to be the most promising method [4]. Indeed, a semiconductor–superconductor nanowire was manufactured to confirm the prediction of the theory [12][13][14]. The second topological superconducting system that was realized

Beyond Moore’s technologies: operation principles of a superconductor alternative

• Igor I. Soloviev,
• Nikolay V. Klenov,
• Sergey V. Bakurskiy,
• Mikhail Yu. Kupriyanov,
• Alexander L. Gudkov and
• Anatoli S. Sidorenko

Beilstein J. Nanotechnol. 2017, 8, 2689–2710, doi:10.3762/bjnano.8.269

• superconducting logic circuits are the superconductivity effects, the quantization of magnetic flux and the Josephson effect. The first one enables ballistic signal transfer not limited by a power necessary to charge the capacitance of interconnect lines. It provides the biggest advantage in energy efficiency in

• ferromagnetic layer(s)) serves for injection of spin-polarized electrons in a common superconducting electrode of both junctions, thus suppressing its superconductivity. This manifests itself as redistribution of the superconducting current flowing through this electrode or as degradation of the critical

• in the middle to which the third terminal tip is connected. A current pulse from the third terminal switches off the superconductivity of the nanowire, that is similar to SFT operation to some extent. Unlike a Josephson junction, the nanowire in the resistive state possesses several kiloohms of

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

• effects are metal-insulator transitions or superconductivity which were reported for organic charge-transfer crystals realized by a combination of strongly electron-accepting and strongly electron-donating molecules [9][10]. Recently, a heterostructure of manganese phthalocyanine (MnPc) and structurally

Coexistence of strongly buckled germanene phases on Al(111)

• Weimin Wang and
• Roger I. G. Uhrberg

Beilstein J. Nanotechnol. 2017, 8, 1946–1951, doi:10.3762/bjnano.8.195

• materials. In similarity with graphene, some other materials are also predicted to show a linear electron dispersion near the Fermi level. Other important properties/phenomena that make 2D materials particularly interesting for incorporation in various devices are, magnetism, superconductivity, Rashba type

Near-infrared-responsive, superparamagnetic Au@Co nanochains

• Varadee Vittur,
• Arati G. Kolhatkar,
• Shreya Shah,
• Irene Rusakova,
• Dmitri Litvinov and
• T. Randall Lee

Beilstein J. Nanotechnol. 2017, 8, 1680–1687, doi:10.3762/bjnano.8.168

• Varadee Vittur Arati G. Kolhatkar Shreya Shah Irene Rusakova Dmitri Litvinov T. Randall Lee Department of Chemistry and the Texas Center for Superconductivity, University of Houston, 4800 Calhoun Road, Houston, TX 77204, USA Department of Physics and the Texas Center for Superconductivity

• . Acknowledgements We thank the Asian Office of Aerospace Research and Development (AFOSR/AOARD FA2386-16-1-4067), the Robert A. Welch Foundation (E-1320), and the Texas Center for Superconductivity for supporting this research.