Microwave photon detection by an Al Josephson junction

• Leonid S. Revin,
• Andrey L. Pankratov,
• Anna V. Gordeeva,
• Anton A. Yablokov,
• Igor V. Rakut,
• Victor O. Zbrozhek and
• Leonid S. Kuzmin

Beilstein J. Nanotechnol. 2020, 11, 960–965, doi:10.3762/bjnano.11.80

• the JJ constantly inspires new applications, such as thermometry [8][9], noise statistics [10][11][12] and single-photon detection [13]. There are, at least, two different approaches for the practical realization of single-photon detectors based on Josephson junctions, both having their advantages and

A Josephson junction based on a highly disordered superconductor/low-resistivity normal metal bilayer

• Pavel M. Marychev and
• Denis Yu. Vodolazov

Beilstein J. Nanotechnol. 2020, 11, 858–865, doi:10.3762/bjnano.11.71

• junction; Joule heating; Introduction Josephson junctions are of interest for applications such as voltage standards [1], SQUID magnetometers [2], particle detectors [3], and energy-efficient superconductor logic and memory circuits [4][5]. These applications need to have a large critical current Ic to

• achieve high noise immunity. Also many of these applications require to have a nonhysteretic current–voltage characteristic (IVC) and a large characteristic voltage Vc = IcRn, where Rn is the normal-state resistance of the junction. Tunnel superconductor–insulator–superconductor (SIS) Josephson junctions

• in SIS junctions requires an external resistor or a more complex circuitry. S-c-S Josephson junctions (where “c” is a geometric constriction) have a small capacitance of the weak link and a high critical current (about the magnitude of the depairing current of a superconductor), which allows one to

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

• junction technology is currently implied to be used for the logics fabrication, however, hybrid Josephson junctions incorporating magnetic components are also considered for the mainframe computation components [9][14][15][16][17][18][19], and cache and main memories [8][20][21][22][23][24][25]. It is

• argued that the use of magnetic Josephson junctions in single-flux quantum electronics significantly reduces the number of junctions and interconnects in the circuits [26] and also has other important advantages such as wide operation margins and low bit-error rate [27]. The magnetic material has to be

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

• attention and have been extensively studied both experimentally [32][33][34][35][36][37][38][39][40][41] and theoretically [23][45][76][77][78][79][80]. For instance, the current–voltage characteristics (CVC) of SIFS Josephson junctions with a strong insulating layer were studied in [45]. They exhibit

Unipolar magnetic field pulses as an advantageous tool for ultrafast operations in superconducting Josephson “atoms”

• Daria V. Popolitova,
• Nikolay V. Klenov,
• Igor I. Soloviev,
• Sergey V. Bakurskiy and
• Olga V. Tikhonova

Beilstein J. Nanotechnol. 2019, 10, 1548–1558, doi:10.3762/bjnano.10.152

• superconducting artificial atoms. However, to be specific, we will consider the well-known flux qubit scheme: a superconducting ring with three Josephson junctions (see inset in Figure 1). The potential energy of the system takes the double-well form when the characteristic Josephson energies of the three

• quantum (RSFQ) circuits. Namely, a Josephson transmission line realized as a parallel array of lumped Josephson junctions coupled by superconducting inductances was chosen as a control line supporting the flux to be quantized. One cell of the transmission line was magnetically coupled with the qubit so

• Josephson transmission line, here Josephson junctions are substituted by superconducting adiabatic logic cells [33][34][35][36]. This allows one to transfer data not in the form of the presence or absence of quanta, but in the direction of the currents circulating in the superconducting circuits (excluding

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

• and the thin superconductor spacers (see, e.g., [8]). To check this hypothesis we calculated the critical current of S/F/s/F/S and S/F/N/F/S Josephson junctions (Figure 1). The calculations were performed in the framework of the Usadel equation [17] with Kupriyanov–Lukichev conditions [18] in an

• AP alignments. The calculations were performed for the same set of parameters as in Figure 1. From Figure 2a it follows that the considered structure is a series connection of s/F1/s and s/F2/s Josephson junctions with the weakest link located in the middle of the structure. Figure 2b shows the

• possibility to control the superconducting properties of Josephson junctions by switching between parallel and antiparallel alignment in a periodic F/s weak link. We experimentally showed that such a switching is feasible using the concept of a periodic pseudo spin valve. We note that such a design will allow

A zero-dimensional topologically nontrivial state in a superconducting quantum dot

• Pasquale Marra,
• Alessandro Braggio and
• Roberta Citro

Beilstein J. Nanotechnol. 2018, 9, 1705–1714, doi:10.3762/bjnano.9.162

• temperatures. Keywords: Josephson effect; Josephson junctions; quantum dots; superconducting quantum dots; topological states; topological superconductors; Introduction Since the discovery of the quantum Hall effect [1][2] and the theoretical prediction of Majorana bound states in triplet superconductors [3

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

• first motivate the present study. (For a more detailed discussion and references, see below.) Our manuscript addresses the supercurrent flowing in Josephson junctions with a magnetic impurity. By considering Josephson junctions between a topological superconductor and a non-topological superconductor

• , we naturally extend previous works on Josephson junctions with a magnetic impurity between two conventional superconductors, as well as other works on Josephson junctions between topological and non-topological superconductors but without a magnetic impurity. In the simplest description, Josephson

• junctions between topological and non-topological supeconductors carry no supercurrent. Instead, a supercurrent can flow only with certain deviations from the idealized model description. The presence of a magnetic impurity in the junction is one of these deviations, and this effect allows for novel

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

• fractional Josephson effect was also studied in the nanowire Josephson junctions, where novel Shapiro steps and Josephson radiations have been reported. Recently, the Coulomb blockade spectroscopy was exploited on finite-size nanowire segments that form nanowire islands with two Majorana bound states

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

• . The corresponding available density of Josephson junctions on a chip is 107/cm2. The complexity of superconducting circuits becomes limited to 2.5 million junctions per square centimeter under the assumption that only a quarter of the chip area can be occupied by Josephson junctions (with taking

• shown in Figure 2. It is a parallel array of superconducting loops composed of Josephson junctions (shown by crosses) and superconducting inductances. This structure is called the Josephson transmission line (JTL). SFQ can be transferred along this JTL by successive switchings of Josephson junctions

• switching of Josephson junctions resulting in the reproduction (or not) of SFQs. In the RSFQ convention [16][23], the arrival of an SFQ pulse during a clock period to a logic cell has the meaning of a binary “1”, while the absence of the SFQ pulse means “0”. Figure 3 illustrates an example of clocked

Anodization-based process for the fabrication of all niobium nitride Josephson junction structures

• Massimiliano Lucci,
• Ivano Ottaviani,
• Matteo Cirillo,
• Fabio De Matteis,
• Roberto Francini,
• Vittorio Merlo and
• Ivan Davoli

Beilstein J. Nanotechnol. 2017, 8, 539–546, doi:10.3762/bjnano.8.58

• investigate its mechanical and adhesion properties. The transport properties of NbN/AlN/NbN Josephson junctions obtained as a result of the above described fabrication process were measured in liquid helium at 4.2 K. Keywords: Josephson effect; superconductors; thin films; tunneling; Introduction Niobium

• different thickness, namely 175 nm, 2 nm and 360 nm. The choice of the thicknesses of the films was imposed by design requirements. The Josephson junctions (Figure 12) were realized using UV lithography and a lift-off process. The (10 × 10) µm2 junction areas were defined anodizing the top layer following

• the other growth parameters. Similarly, it is possible to predict and obtain the conductive or insulating properties of AlN. We have adapted the deposition process to the lithographic and technological needs for the realization of superconductor/insulator/superconductor and Josephson junctions devices

Thickness-modulated tungsten–carbon superconducting nanostructures grown by focused ion beam induced deposition for vortex pinning up to high magnetic fields

• Ismael García Serrano,
• Javier Sesé,
• Isabel Guillamón,
• Hermann Suderow,
• Sebastián Vieira,
• Manuel Ricardo Ibarra and
• José María De Teresa

Beilstein J. Nanotechnol. 2016, 7, 1698–1708, doi:10.3762/bjnano.7.162

• pinning potentials suitable for Josephson junctions [19] and nano-SQUID devices [54] operating in large field and temperature ranges. Experimental Samples with five different periodicity values of the thickness modulation (60, 80, 100, 120 and 140 nm) and one additional flat sample without modulation were

Adiabatic superconducting cells for ultra-low-power artificial neural networks

• Andrey E. Schegolev,
• Nikolay V. Klenov,
• Igor I. Soloviev and
• Maxim V. Tereshonok

Beilstein J. Nanotechnol. 2016, 7, 1397–1403, doi:10.3762/bjnano.7.130

• (two or three) Josephson junctions. This presents a distinct opportunity for the development of energy efficient, high density, fast superconducting ANNs for cognitive receiving systems. It was shown that a Josephson structure (e.g., a bi-SQUID or a SQIF) transfer function can be precisely designed by

• nanotechnology [29] with the implementation of nanoscale Josephson junctions (e.g., on the basis of variable thickness bridges [30]). Finally, comparison of the probability of error curves for RBF ANNs based on the proposed neuron with those based on an ideal neuron with a Gaussian activation function is

• connection of two s-cells in order to obtain a bell-shaped transfer function from two sigmoid functions. Note that the resulting scheme is quite analogous to the above mentioned QFP. The cell is a two-junction interferometer with a total normalized inductance l, composed of two Josephson junctions J1 and J2

Magnetic reversal dynamics of a quantum system on a picosecond timescale

• Nikolay V. Klenov,
• Alexey V. Kuznetsov,
• Igor I. Soloviev,
• Sergey V. Bakurskiy and
• Olga V. Tikhonova

Beilstein J. Nanotechnol. 2015, 6, 1946–1956, doi:10.3762/bjnano.6.199

• Josephson junctions have been successfully created. The control technique developed for these effectively two-level pseudo-atomic systems allows for the implementation of single- and multi-qubit operations. Moreover, the observation of effects referred to as “quantum optics on a chip” is possible, leading