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## Nonequilibrium effects in tunnel Josephson junctions

Physical Review B: Condensed Matter and Materials Physics. 2005. Vol. 72. No. 1. P. 014501-1-014501-12.

We study nonequilibrium effects in current transport through voltage biased tunnel junction with long diffusive superconducting leads at low applied voltage eV << 2 Delta, and finite temperatures. Due to a small value of the Josephson frequency, the quasiparticle spectrum adiabatically follows the time evolution of the superconducting phase difference, which results in the formation of oscillating bound states in the vicinity of the tunnel junction (Andreev band). The quasiparticles trapped by the Andreev band generate higher even harmonics of the Josephson ac current, and also, in the presence of inelastic scattering, a nonequilibrium dc current, which may considerably exceed the dc quasiparticle current given by the tunnel model. The distribution of traveling quasiparticles also deviates from the equilibrium due to the spectrum oscillations, which results in an additional contribution to the dc current, proportional to root V.

Vasenko A. S., Golubov A. A., Kupriyanov M. Y. et al., Physical Review B: Condensed Matter and Materials Physics 2008 Vol. 77 No. 13 P. 134507-1-134507-9

We investigate superconductor/insulator/ferromagnet/superconductor tunnel Josephson junctions in the dirty limit using the quasiclassical theory. We formulate a quantitative model describing the oscillations of critical current as a function of thickness of the ferromagnetic layer and use this model to fit recent experimental data. We also calculate quantitatively the density of states (DOS) in this type ...

Added: November 29, 2017

Mal'shukov A., Physical Review B: Condensed Matter and Materials Physics 2020 Vol. 102 P. 134509-1-134509-5

The Zeeman interaction results in spontaneous current through a Josephson contact with a spin-orbit coupled
normal metal, even in the absence of any voltage, or phase bias. In the case of the Rashba spin-orbit coupling
of electrons in a two-dimensional (2D) electron gas this effect takes place for the Zeeman field which is parallel
to the 2D system ...

Added: January 20, 2021

Kawabata S., Tanaka Y., Golubov A. A. et al., Journal of Magnetism and Magnetic Materials 2012 Vol. 324 P. 3467-3470

Ferromagnetic-insulator (FI) based Josephson junctions are promising candidates for a coherent superconducting quantum bit as well as a classical superconducting logic circuit. Recently the appearance of an intriguing atomic-scale 0-pi transition has been theoretically predicted. In order to uncover the mechanism of this phenomena, we numerically calculate the spectrum of Andreev bound states in a ...

Added: September 28, 2015

Arutyunov K., Lehtinen J. S., Beilstein Journal of Nanotechnology 2020 Vol. 11 P. 417-420

Chain of superconductor-insulator-superconductor junctions based on Al-AlOx-Al... lift-off fabricated nanostructures was measured at ultra-low temperatures. At zero magnetic field the low current bias dynamic resistance can reach values ~1011 W. The system has been proved to provide a decent quality current biasing circuit enabling observation of Coulomb blockade and Bloch oscillations in ultra-narrow Ti nanowires ...

Added: September 18, 2020

Arutyunov K. Yu., Chernyaev S. A., Karabassov T. et al., Journal of Physics: Condensed Matter 2018 Vol. 30 No. 343001 P. 1-16

Rapid development of micro- and nanofabrication methods have provoked interest
and enabled experimental studies of electronic properties of a vast class of (sub)micrometersize
solid state systems. Mesoscopic-size hybrid structures, containing superconducting
elements, have become interesting objects for basic research studies and various applications,
ranging from medical and astrophysical sensors to quantum computing. One of the
most important aspects of physics, ...

Added: July 31, 2018

Мальшуков А. Г., Physical Review B: Condensed Matter and Materials Physics 2019 Vol. 100 P. 035301-1-035301-7

A nonstationary anomalous Hall current is calculated for a voltage biased Josephson junction, which is composed of two s-wave superconducting contacts deposited on the top of a three-dimensional topological insulator (TI). A homogeneous Zeeman field was assumed at the surface of the TI. The problem has been considered within the ballistic approximation and on the ...

Added: March 11, 2020

Vodolazov D. Y., Manova N., Korneeva Y. et al., Physical Review Applied 2020 Vol. 14 No. 4 P. 044041

We experimentally study timing jitter of single-photon detection by NbN superconducting strips with
width w ranging from 190 nm to 3 μm. We find that timing jitter of both narrow (190 nm) and micron- wide strips is about 40 ps at currents where internal detection efficiency η saturates and it is close to our instrumental jitter. ...

Added: December 7, 2020

Manova N., Smirnov E., Korneeva Y. et al., Journal of Physics: Conference Series 2019 Vol. 1410 P. 1-5

We develop large area superconducting single-photon detector SSPD with a micron- wide strip suitable for free-space coupling or packaging with multi-mode optical fibres. The detector sensitive area is 20 ?m in diameter. In near infrared (1330 nm wavelength) our SSPD exhibits above 30% detection efficiency with low dark counts and 45 ps timing jitter. ...

Added: December 7, 2020

Dolgirev P. E., Kalenkov M. S., Zaikin Andrei D., Scientific Reports 2019 Vol. 9 P. 1-9

Proximity induced quantum coherence of electrons in multi-terminal voltage-driven hybrid normalsuperconducting
nanostructures may result in a non-trivial interplay between topology-dependent
Josephson and Aharonov-Bohm effects. We elucidate a trade-off between stimulation of the voltagedependent
Josephson current due to non-equilibrium effects and quantum dephasing of quasiparticles
causing reduction of both Josephson and Aharonov-Bohm currents. We also predict phase-shifted
quantum coherent oscillations of ...

Added: March 11, 2019

Bezuglyi E. V., Vasenko A. S., Bratus E. N. et al., Superconductor Science and Technology 2007 Vol. 20 No. 6 P. 529-541

We formulate a theoretical framework to describe multiparticle current transport in planar superconducting tunnel junctions with diffusive electrodes. The approach is based on the direct solving of quasiclassical Keldysh - Green function equations for nonequilibrium superconductors, and consists of a combination of circuit theory analysis and improved perturbation expansion. The theory predicts a much greater ...

Added: November 29, 2017

Bezuglyi E. V., Vasenko A. S., Bratus E. N. et al., Physical Review B: Condensed Matter and Materials Physics 2006 Vol. 73 No. 22 P. 220506-1-220506-4

We calculate the subgap current in planar superconducting tunnel junctions with thin-film diffusive leads. It is found that the subharmonic gap structure of the tunnel current scales with an effective tunneling transparency which may exceed the junction transparency by up to two orders of magnitude depending on the junction geometry and the ratio between the ...

Added: November 29, 2017

Kawabata S., Tanaka Y., Golubov A. A. et al., Physica C: Superconductivity and its Applications 2011 Vol. 471 No. 21-22 P. 1199-1201

We show a perturbation theory of the Josephson transport through ferromagnetic insulators (FIs). Recently we have found that the appearance of the atomic scale 0-pi transition in such junctions based on numerical calculations. In order to explore the mechanism of this anomalous transition, we have analytically calculated the Josephson current using the tunneling Hamiltonian theory ...

Added: November 29, 2017

M. Polyakova, Florya I., Semenov A. et al., Journal of Physics: Conference Series 2019 Vol. 1410 P. 012166

We present data of quantum detector tomography for the samples specifically optimized for this problem. Using this method, we take results of hot-spot correlation length of 17 ± 2 nm.
1. ...

Added: December 7, 2020

Dolgirev P. E., Kalenkov M. S., Zaikin Andrei D., Physica Status Solidi - Rapid Research Letters 2019 Vol. 13 No. 1 P. 1800252-1-1800252-5

We theoretically investigate coherent oscillations of the thermopower S as a function of the magnetic flux Ф in six-terminal Andreev interferometers. We demonstrate that the thermopower behavior is determined by a number of
contributions originating from the Josephson- and Aharonov–Bohm-like effects as well as from electron–hole asymmetry. The relative weight of these contributions depends on the ...

Added: October 26, 2018

Arutyunov K. Yu., Auraneva H. P., Vasenko A. S., Physical Review B: Condensed Matter and Materials Physics 2011 Vol. 83 No. 10 P. 104509-1-104509-7

Spatially resolved relaxation of nonequilibrium quasiparticles in a superconductor at ultralow temperatures was experimentally studied. It was found that the quasiparticle injection through a tunnel junction results in the modification of the shape of the I-V characteristic of a remote "detector" junction. The effect depends on the temperature, injection current, and proximity to the injector. ...

Added: November 29, 2017

Kemmler M., Weides M., Weiler M. et al., Physical Review B: Condensed Matter and Materials Physics 2010 Vol. 81 No. 5 P. 054522-1-054522-8

We present a detailed analysis of the dependence of the critical current I(c) on an in-plane magnetic field B of 0, pi, and 0-pi superconductor-insulator-ferromagnet-superconductor Josephson junctions. I(c)(B) of the 0 and the pi junction closely follows a Fraunhofer pattern, indicating a homogeneous critical current density j(c)(x). The maximum of I(c)(B) is slightly shifted along ...

Added: November 29, 2017

Sasaki A., Ikegaya S., Habe T. et al., Physical Review B: Condensed Matter and Materials Physics 2020 Vol. 101 No. 184501 P. 184501-1-184501-6

We study theoretically the Josephson effect between two two-band superconductors respecting time-reversal
symmetry, where we assume a spin-singlet s-wave pair potential in each conduction band. The superconducting
phase at the first band ϕ1 and that at the second band ϕ2 characterize a two-band superconducting state. We
consider a Josephson junction where an insulating barrier separates two such two-band ...

Added: October 8, 2020

Demenev A. A., Grishina Y. V., Larionov A. V. et al., Physical Review B: Condensed Matter and Materials Physics 2017 Vol. 96 No. 15 P. 155308-1-155308-10

We address polarization instability in a freely decaying polariton condensate created by 2-ps-long linearly polarized laser pulses in the upper sublevel of the lower-polariton (LP) branch in a GaAs-based microcavity with reduced symmetry. The generated linearly polarized condensate is found to lose its stability at excitation densities above the threshold value: it passes into the ...

Added: February 15, 2018

Saveskul N. A., Titova N. A., Baeva E. et al., Physical Review Applied 2019 Vol. 12 No. 5 P. 1-10

We analyze the evolution of the normal and superconducting properties of epitaxial TiN films, characterized by high Ioffe-Regel parameter values, as a function of the film thickness. As the film thickness decreases, we observe an increase of the residual resistivity, that becomes dominated by diffusive surface scattering for d≤20nm. At the same time, a substantial thickness-dependent ...

Added: October 10, 2019

Ryabchun S., Goltsman G., Kardakova A. et al., Physical Review B: Condensed Matter and Materials Physics 2016 Vol. 93 No. 6 P. 064506-064517

We report a study of the relaxation time of the restoration of the resistive superconducting state in single crystalline boron-doped diamond using amplitude-modulated absorption of (sub-)THz radiation (AMAR). The films grown on an insulating diamond substrate have a low carrier density of about 2.5×1021cm−3 and a critical temperature of about 2K. By changing the modulation ...

Added: August 15, 2016

Ryazanov V., Caruso R., Massarotti D. et al., IEEE Transactions on Applied Superconductivity 2018 Vol. 28 No. 7 P. 1800606-1-1800606-6

In this paper, we give a characterization of the RF effect of memory switching on Nb-Al/AlOx-(Nb)-Pd0.99Fe0.01-Nb Josephson junctions as a function of magnetic field pulse amplitude and duration, alongside with an electrodynamical characterization of such junctions, in comparison with standard Nb-Al/AlOx-Nb tunnel junctions. The use of microwaves to tune the switching parameters of magnetic Josephson ...

Added: February 21, 2019

Antipov A., Seleznev V., Vakhtomin Y. et al., IOP Conference Series: Materials Science and Engineering (MSE) 2020 Vol. 781 No. 1 P. 012011-1-012011-5

Spectral characteristics of WSi and NbN superconducting single-photon detectors with different surface resistance and width of nanowire strips have been investigated in the wavelength range of 1.3-2.5 µm. WSi structures with narrower strips demonstrated better performance for detection of single photons in longer wavelength range. The difference in normalized photon count rate for such structures ...

Added: December 10, 2020

Budkov Y., Kolesnikov A. L., Polymer Science - Series C 2018 Vol. 60 No. Supplement 1 P. 148-159

Theoretical models of the conformational behavior of flexible polymer chains in mixed solvents enunciated in the world literature during the last decade are critically reviewed. Models describing different mechanisms of coil-to-globule transitions in a good solvent induced by cosolvent addition are highlighted. Special attention is given to the analysis of theoretical approaches to describing the ...

Added: November 30, 2018

Kalmykov A., Melentiev P., Balykin V., Laser Physics Letters 2020 Vol. 17 No. 4 P. 045901

In this paper we present measurements and comparison of SPP propagation length at the practically important telecom wavelength (1560 nm) as well as in the near-infrared and visible spectral ranges. The measurements were carried out for plane SPP waves excited on Ag film surface using optical microscopy of SPP waves in the far field. We ...

Added: January 15, 2021