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

• insulating interlayers. The main specific feature of these structures is the intentional oxidation of both superconductor/ferromagnet (S/F) interfaces. We study the variation of the critical temperature of our systems due to switching between parallel and antiparallel configurations of the magnetizations of

• superconducting spin valves. Keywords: ferromagnet; insulator layers; proximity effect; superconducting spin-valve; superconductor; Introduction Models and specific realizations of the superconducting spin valve (SSV) have been the subject of intensive research over the past 25 years [1][2][3][4][5][6][7][8][9

Modulated critical currents of spin-transfer torque-induced resistance changes in NiCu/Cu multilayered nanowires

• Mengqi Fu,
• Roman Hartmann,
• Julian Braun,
• Sergej Andreev,
• Torsten Pietsch and
• Elke Scheer

Beilstein J. Nanotechnol. 2024, 15, 360–366, doi:10.3762/bjnano.15.32

• macrospin approximation of free layers breaks down to nonuniform excitations, which means the magnetization of the ferromagnet is spatially nonuniform [27][28]. Nonuniform excitations occur in a very thin magnetic layer when the spin accumulation on its two sides is different. Under the critical current

Frontiers of nanoelectronics: intrinsic Josephson effect and prospects of superconducting spintronics

• Anatolie S. Sidorenko,
• Horst Hahn and
• Vladimir Krasnov

Beilstein J. Nanotechnol. 2023, 14, 79–82, doi:10.3762/bjnano.14.9

• –ferromagnet–superconductor (SFS) structures have been predicted and calculated [26]. A quantitative study of the density of states (DOS) in bulk superconductor/ferromagnetic (S/F) bilayers in the diffusive limit has been presented. In addition, an analysis of the dependencies of DOS on magnetic and spin–orbit

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

• –orbit scattering. For practical reasons, we propose the analytical solution for the density of states in SF bilayers in the case of a thin ferromagnet and low transparency of the SF interface. This solution is confirmed by numerical calculations using a self-consistent two-step iterative method. The

• behavior of DOS dependencies on magnetic and spin–orbit scattering times is discussed. Keywords: density of states; Josephson junctions; proximity effect; superconductivity; superconductor/ferromagnet hybrid nanostructures; Introduction It is well-known that superconductivity can be induced in a non

• ]. In this work, we consider a diffusive SF bilayer, assuming a relatively low interface transparency and the presence of magnetic and spin–orbit scattering. For this purpose, the Kupriyanov–Lukichev (KL) boundary conditions at the superconductor/ferromagnet interface are perfectly suitable [83]. We

Nonlinear features of the superconductor–ferromagnet–superconductor φ₀ Josephson junction in the ferromagnetic resonance region

• Aliasghar Janalizadeh,
• Ilhom R. Rahmonov,
• Sara A. Abdelmoneim,
• Yury M. Shukrinov and
• Mohammad R. Kolahchi

Beilstein J. Nanotechnol. 2022, 13, 1155–1166, doi:10.3762/bjnano.13.97

• difference with the magnetic moment of a ferromagnet in a φ0 junction leads to a number of unique features important for superconducting spintronics and modern information technology [1][2][3][4][5]. It allows one to control the magnetization precession by the superconducting current and affects the current

• –voltage (I–V) characteristics by magnetic dynamics in the ferromagnet, in particular, to create a DC component in the superconducting current [6][7][8]. A remarkable manifestation of this coupling is the possibility to stimulate a magnetization reversal in the ferromagnetic layer by applying a current

• characteristics. The generated current I0 can be expressed through the amplitude of my and the SOI parameter r, with (ωJ) being the frequency response of my. At small model parameters α ≪ Gr ≪ 1 of a superconductor-ferromagnet-superconductor (SFS) φ0 Josephson junction, states with a negative differential

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

• superconductor/ferromagnet hybrid absorbers based on Al/Fe films, as the previous samples. However, there are different oxidation parameters. This work aims to improve our new fit methodology, which takes into account both leakage and Andreev currents and also uses the sixth power of phonon and electron

Ultrafast signatures of magnetic inhomogeneity in Pd_1−xFe_x (x ≤ 0.08) epitaxial thin films

• Andrey V. Petrov,
• Sergey I. Nikitin,
• Lenar R. Tagirov,
• Amir I. Gumarov,
• Igor V. Yanilkin and
• Roman V. Yusupov

Beilstein J. Nanotechnol. 2022, 13, 836–844, doi:10.3762/bjnano.13.74

• ferromagnetic state causes a qualitative change of both the reflectivity and the magneto-optical Kerr effect transients. A nanoscale magnetic inhomogeneity of the ferromagnet/paramagnet type inherent in the palladium-rich Pd1−xFex alloys reveals itself through the occurrence of a relatively slow, 10–25 ps

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

• 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

• confident that our theory will in the future provide further motivation for the interesting physics of ferromagnetic insulators and the proximity effect in ferromagnet or antiferromagnet–superconductor heterostructures. (a) The experimental setup of the FI–S bilayer. The differential conductance is measured

Controllable two- and three-state magnetization switching in single-layer epitaxial Pd_1−xFe_x films and an epitaxial Pd_0.92Fe_0.08/Ag/Pd_0.96Fe_0.04 heterostructure

• Igor V. Yanilkin,
• Amir I. Gumarov,
• Gulnaz F. Gizzatullina,
• Roman V. Yusupov and
• Lenar R. Tagirov

Beilstein J. Nanotechnol. 2022, 13, 334–343, doi:10.3762/bjnano.13.28

• demagnetization occurred on a time scale of approx. 100 s [31]. Conclusion Detailed measurements of the magnetoresistance have shown that the Pd0.92Fe0.08 epitaxial film, being an easy-plane ferromagnet with a pronounced in-plane anisotropy, undergoes magnetization switching between two (with collinear

In situ transport characterization of magnetic states in Nb/Co superconductor/ferromagnet heterostructures

• Olena M. Kapran,
• Roman Morari,
• Taras Golod,
• Evgenii A. Borodianskyi,
• Vladimir Boian,
• Andrei Prepelita,
• Nikolay Klenov,
• Anatoli S. Sidorenko and
• Vladimir M. Krasnov

Beilstein J. Nanotechnol. 2021, 12, 913–923, doi:10.3762/bjnano.12.68

• Functional Nanostructures, Orel State University named after I.S. Turgenev, 302026, Russia 10.3762/bjnano.12.68 Abstract Employment of the non-trivial proximity effect in superconductor/ferromagnet (S/F) heterostructures for the creation of novel superconducting devices requires accurate control of magnetic

• ][34][35] in various superconductor/ferromagnet (S/F) heterostructures. It is anticipated, that this phenomenon can be employed for the creation of novel superconducting devices, in which the supercurrent is determined and controlled by the magnetic state of the heterostructure, that is, by the

Molecular dynamics modeling of the influence forming process parameters on the structure and morphology of a superconducting spin valve

• Alexander Vakhrushev,
• Aleksey Fedotov,
• Vladimir Boian,
• Roman Morari and
• Anatolie Sidorenko

Beilstein J. Nanotechnol. 2020, 11, 1776–1788, doi:10.3762/bjnano.11.160

• quantum-mechanical transparency of the interface, TF, was assigned. Here, they considered the effect of the mutual solubility of the metals (of a superconductor and a ferromagnet) on the quantum-mechanical transparency. The transparency parameter of the interface for completely non-wetting metals, such as

Adsorption and self-assembly of porphyrins on ultrathin CoO films on Ir(100)

• Feifei Xiang,
• Tobias Schmitt,
• Marco Raschmann and
• M. Alexander Schneider

Beilstein J. Nanotechnol. 2020, 11, 1516–1524, doi:10.3762/bjnano.11.134

• , it is also an anti-ferromagnet due to electron correlation effects and it shows catalytic activity [14][15][16][17]. As a thin film grown on Ir(100), the oxide is of extremely high quality [18][19][20] avoiding the complexity that arises from atomic-scale defects in bulk materials [5][6][7][8]. The

Controlling the proximity effect in a Co/Nb multilayer: the properties of electronic transport

• Sergey Bakurskiy,
• Mikhail Kupriyanov,
• Nikolay V. Klenov,
• Igor Soloviev,
• Andrey Schegolev,
• Roman Morari,
• Yury Khaydukov and
• Anatoli S. Sidorenko

Beilstein J. Nanotechnol. 2020, 11, 1336–1345, doi:10.3762/bjnano.11.118

• enhancement of the effective exchange field in this artificial ferromagnet. Previously, the properties of [Co(1.5 nm)/Nb(8 nm)/Co(2.5 nm)/Nb(8 nm)]6 multilayer structures for cryogenic memory applications were studied using polarized neutron scattering and magnetometry techniques [9]. In particular, the

Proximity effect in [Nb(1.5 nm)/Fe(x)]₁₀/Nb(50 nm) superconductor/ferromagnet heterostructures

• Yury Khaydukov,
• Sabine Pütter,
• Laura Guasco,
• Roman Morari,
• Gideok Kim,
• Thomas Keller,
• Anatolie Sidorenko and
• Bernhard Keimer

Beilstein J. Nanotechnol. 2020, 11, 1254–1263, doi:10.3762/bjnano.11.109

• the thickness of the Fe layer to x = 4 nm the intermediate phase disappears. We attribute the intermediate state to proximity induced non-homogeneous superconductivity in the structure. Keywords: ferromagnet; iron (Fe); mixed state; neutron reflectometry; niobium (Nb); proximity effects

• ; superconductor; Introduction Superconductor(S)/ferromagnet(F) heterostructures are intensively studied systems, which are interesting for fundamental physics due to a big number of predicted and detected phenomena such as the appearance of non-uniform superconducting states (see reviews [1][2][3]). Among these

• between 60% and 90%. This alloy has properties of a weak ferromagnet with a Curie temperature of Tm ≈ 100 K. The proximity of this weak F layer to a thick superconductor leads to the presence of an intermediate phase between normal and superconducting state. This phase is characterized by a suppressed

Epitaxial growth and superconducting properties of thin-film PdFe/VN and VN/PdFe bilayers on MgO(001) substrates

• Wael M. Mohammed,
• Igor V. Yanilkin,
• Amir I. Gumarov,
• Airat G. Kiiamov,
• Roman V. Yusupov and
• Lenar R. Tagirov

Beilstein J. Nanotechnol. 2020, 11, 807–813, doi:10.3762/bjnano.11.65

• ; epitaxial superconductor–ferromagnet heterostructure; palladium–iron alloy (PdFe); vanadium nitride (VN); superconducting spintronics; Introduction Since its invention, rapid single-flux quantum (RSFQ) logic [1][2] based on superconducting digital electronics has been seriously considered as an alternative

• of niobium as a superconductor with a Pd1−xFex alloy as a soft and weak ferromagnet was considered as material of choice for superconducting magnetic random access memories (MRAM) [8][29][30]. However, no further developments towards a prototype using a Pd1−xFex alloy have been demonstrated. There

• ferromagnet with a low coercive field [41]. It is important that magnetic properties of epitaxial Pd1−xFex films are precisely controlled with the iron content x [41], and a perfect cube-on-cube epitaxy is realized with either the MgO(001) substrate or with the superconducting VN layers in any sequence

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

• Physical Institute, Russian Academy of Sciences, 119991 Moscow, Russia 10.3762/bjnano.11.19 Abstract We present a quantitative study of the current–voltage characteristics (CVC) of SFIFS Josephson junctions (S = bulk superconductor, F = metallic ferromagnet, I = insulating barrier) with weak ferromagnetic

• 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

• , with thicknesses df1 and df2. The system contains three interfaces: two S/F (superconductor/ferromagnet) boundaries and one tunnel F-I-F interface. Each of these interfaces is described by the dimensionless parameter γBj = RBjσn/ξn (j = 0, 1, 2), which is proportional to the resistance RBj across the

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

• configuration efficiently draws off the spin-polarized Cooper pairs from the space between the HA and Ni layers. Our results indicate a significant potential of the concept of a superconducting spin-valve multilayer comprising a half-metallic ferromagnet, recently proposed by A. Singh et al., Phys. Rev. X 2015

• , 5, 021019, in achieving large values of the switching effect. Keywords: ferromagnet; proximity effect; superconductor; Introduction For decades, metallic thin-film heterostructures have been in the in the focus of fundamental research in condensed matter physics and materials science. They show

• generalize the results of the pioneering work by Singh and co-workers [14]. Previously, we have shown the advantages of using the Heusler alloy (HA) Co2Cr1−xFexAly as a weak ferromagnet in the F2 layer of the F1/F2/S SSV structure [15]. Therefore, instead of CrO2, which in accordance with the data on point

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

• magnitude of the temperature (b). The red lines correspond to the case when the exchange energies in both layers of the ferromagnet are equal in magnitude, and the magnetization vectors lying in the plane of the magnetic layers are parallel (P). The blue lines are for the case when the exchange energies

Size limits of magnetic-domain engineering in continuous in-plane exchange-bias prototype films

• Alexander Gaul,
• Daniel Emmrich,
• Timo Ueltzhöffer,
• Henning Huckfeldt,
• Hatice Doğanay,
• Johanna Hackl,
• Muhammad Imtiaz Khan,
• Daniel M. Gottlob,
• Gregor Hartmann,
• André Beyer,
• Dennis Holzinger,
• Slavomír Nemšák,
• Claus M. Schneider,
• Armin Gölzhäuser,
• Günter Reiss and
• Arno Ehresmann

Beilstein J. Nanotechnol. 2018, 9, 2968–2979, doi:10.3762/bjnano.9.276

• and the ion straggling in the sample. The corresponding lateral range of this effect has been estimated by SRIM [42] simulations to be less than 30 nm at the ferromagnet (F)/antiferromagnet (AF) interface of the investigated layer system (see Appendix, Figure 5) and maximum 90 nm in the deep bulk of

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

• magnitude of the effect is doubled in comparison with the previously studied analogous multilayers with the F2 layer made of the strong ferromagnet Fe. Theoretical analysis shows that a drastic enhancement of the switching effect is due to a smaller exchange field in the heterostructure coming from the

• Heusler film as compared to Fe. This enables to approach an almost ideal theoretical magnitude of the switching in the Heusler-based multilayer with a F2 layer thickness of ca. 1 nm. Keywords: ferromagnet; proximity effect; spin valve; superconductor; Introduction Historically, the first concept to

• the maximum magnitude of the spin-valve effect ΔTc, the thickness dF2 of the F2 layer proximate to the S layer should be of the order or smaller than the penetration depth of the Cooper pairs into the F2 layer, . Here h is the exchange splitting of the conduction band of a ferromagnet. The thinner the

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

Ferrocholesteric–ferronematic transitions induced by shear flow and magnetic field

• Dmitriy V. Makarov,
• Alexander A. Novikov and
• Alexander N. Zakhlevnykh

Beilstein J. Nanotechnol. 2017, 8, 2552–2561, doi:10.3762/bjnano.8.255

• also spirally twisted in space, and in this respect the ferrocholesteric is a liquid crystal analogue of a helicoidal ferromagnet. We apply the magnetic field H = H(cosφH, sinφH, 0) orthogonally to the axis of the ferrocholesteric helix at an angle φH in the shear plane x–y. We assume the anisotropy of

Spin-dependent transport and functional design in organic ferromagnetic devices

• Guichao Hu,
• Shijie Xie,
• Chuankui Wang and
• Carsten Timm

Beilstein J. Nanotechnol. 2017, 8, 1919–1931, doi:10.3762/bjnano.8.192

• phenomenon is explained by transmission and orbital analysis. These works show that organic ferromagnets are promising components for spintronic devices that deserve to be designed and examined in future experiments. Keywords: magnetoresistance; organic ferromagnet; spin-current rectification; spin

• spin coupling only occurs for the odd sites. Since we focus on the effects of the interactions in the organic ferromagnet on transport, we model the electrodes by simple one-dimensional chains described by a single-band tight-binding model with a spin-splitting term [34], Here, denotes the creation

• . Multi-state magnetoresistance in ferromagnet/OF/ferromagnet junctions Further control over an OF device can be gained by employing ferromagnetic electrodes. Ferromagnetic junctions are the basic building blocks for spin valves to realize the magnetoresistance (MR) effect, which is important in

The role of 2D/3D spin-polarization interactions in hybrid copper hydroxide acetate: new insights from first-principles molecular dynamics

• Ziyad Chaker,
• Guido Ori,
• Mauro Boero and
• Carlo Massobrio

Beilstein J. Nanotechnol. 2017, 8, 857–860, doi:10.3762/bjnano.8.86

• between the spin polarizations pertaining to each layer. Therefore, at high pressure, copper hydroxide acetate is a ferromagnet with no changes of spin polarization in the direction perpendicular to the inorganic layers. Keywords: first-principles molecular dynamics; hybrid material; magnetic properties

Nonlinear thermoelectric effects in high-field superconductor-ferromagnet tunnel junctions

• Stefan Kolenda,
• Peter Machon,
• Detlef Beckmann and
• Wolfgang Belzig

Beilstein J. Nanotechnol. 2016, 7, 1579–1585, doi:10.3762/bjnano.7.152

• , thermoelectric effects decrease towards low temperatures, which usually makes them vanishingly small in metal nanostructures in the sub-Kelvin regime. Results: We report on a combined experimental and theoretical investigation of thermoelectric effects in superconductor/ferromagnet hybrid structures. We

• investigate the dependence of thermoelectric currents on the thermal excitation, as well as on the presence of a dc bias voltage across the junction. Conclusion: Large thermoelectric effects are observed in superconductor/ferromagnet and superconductor/normal-metal hybrid structures. The spin-independent

• . Keywords: spintronics, superconductor-ferromagnet hybrids, thermoelectricity; Introduction Electrons in classical superconductors are bound in spin-singlet Cooper pairs, whereas ferromagnetic materials prefer parallel spin alignment. In nanoscale hybrid structures made of superconductors and ferromagnets