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## Microwave response of a chiral Majorana interferometer

Physical Review B: Condensed Matter and Materials Physics. 2021. Vol. 104. No. 3. Article 035434.

Shapiro D., Mirlin A., Shnirman A.

We consider an interferometer based on artificially induced topological superconductivity and chiral one-dimensional (1D) Majorana fermions. The (nontopological) superconducting island inducing the superconducting correlations in the topological substrate is assumed to be floating. This allows probing the physics of interfering Majorana modes via microwave response, i.e., the frequency-dependent impedance between the island and the earth. Namely, charging and discharging of the island is controlled by the time-delayed interference of chiral Majorana excitations in both normal and Andreev channels. We argue that microwave measurements provide a direct way to observe the physics of 1D chiral Majorana modes.

Keywords: электронный транспортquantum field theoryквантовая теория поляElectronic transport in mesoscopic systemsKeldysh diagram techniqueнеравновесные процессыmesoscopic superconductivityмезоскопическая сверхпроводимостьКвантовые флуктуацииMajorana fermionsnoise and fluctuationsnon-equilibrium statistical mechanicsquantum noiseквантовый шуммайорановские связанные состояния

Arutyunov K., Lehtinen J. S., Radkevich A. A. et al., Journal of Magnetism and Magnetic Materials 2018 Vol. 459 P. 356-358

Quasi-one-dimensional superconducting channels host sound-like plasma modes propagating along the
which are associated with fluctuations of the phase of the superconducting order parameter (Mooiji and
1985) [5]. Interaction between these electromagnetic excitations and charge carriers affects the electron density
of states (DOS). I-V characteristics of tunnel S1-I-S2 junctions, where superconducting S2 electrode
nanowire in the regime of quantum fluctuations ...

Added: October 1, 2017

Шапиро Д. С., Scientific Reports 2021 Vol. 11 No. 1 Article 8328

Under nonequilibrium conditions, quantum optical systems reveal unusual properties that might
be distinct from those in condensed matter. The fundamental reason is that photonic eigenstates
can have arbitrary occupation numbers, whereas in electronic systems these are limited by the Pauli principle. Here, we address the steady-state transport of pseudothermal photons between two waveguides connected through a cavity ...

Added: October 31, 2021

Stroganov P. L., Ya.V. Fominov, Physical Review B: Condensed Matter and Materials Physics 2017 Vol. 96 No. 17 P. 174508-1-174508-13

We consider ballistic SQUIDs with spin filtering inside half-metallic ferromagnetic arms. A singlet Cooper pair
cannot pass through an arm in this case, so the Josephson current is entirely due to the Cooper pair splitting, with
two electrons going to different interferometer arms. In order to elucidate the mechanisms of Josephson transport
due to split Cooper pairs, we ...

Added: November 17, 2017

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., M. : Lebedev Institute, 2017

Superconducting properties of metallic nanowires can be entirely different from those of bulk superconductors because of the dominating role played by thermal and quantum fluctuations of the order parameter. For superconducting channels with diameters below ∼ 50 nm fluctuations of the phase of the complex order parameter - the phase slippage - lead to non-zero ...

Added: October 1, 2017

Alex Latyshev, Semenov A. G., Andrei D. Zaikin, Beilstein Journal of Nanotechnology 2020 Vol. 11 P. 1402-1408

We investigate superconductor–insulator quantum phase transitions in ultrathin capacitively coupled superconducting nanowires with proliferating quantum phase slips. We derive a set of coupled Berezinskii–Kosterlitz–Thouless-like renormalization group equations demonstrating that interaction between quantum phase slips in one of the wires gets modified due to the effect of plasma modes propagating in another wire. As a result, ...

Added: October 8, 2020

П.А.Иоселевич, Чукланов Д. А., Письма в Журнал экспериментальной и теоретической физики 2021 Т. 113 № 10 С. 661-668

Рассматривается длинный диффузный контакт Джозефсона, слабой связью в котором является тонкий бислой нормальный металл (N)–ферромагнетик (F), так что N и F образуют параллельные связи между сверхпроводниками S. Показано, что сверхпроводимость в такой слабой связи описывается эффективным одномерным уравнением Узаделя, содержащим ослабленное обменное поле, а также распаривающий член. Механизм распаривания основан на неотъемлемой неоднородности бислоя и ...

Added: October 25, 2021

Akhmedov E., Physical Review D - Particles, Fields, Gravitation and Cosmology 2013 Vol. 87 No. 4 P. 044049

Following Krotov and Polyakov [ Nucl. Phys. B849 410 (2011)], we show that in global de Sitter space its isometry is broken by the loop IR divergences for any invariant vacuum state of the massive scalars. We derive a kinetic equation in global de Sitter space that follows from the Dyson-Schwinger equation of the Schwinger-Keldysh ...

Added: February 27, 2013

Averin D. V., Wang G., A.S. Vasenko, Physical Review B: Condensed Matter and Materials Physics 2020 Vol. 102 No. 14 P. 144516-1-144516-6

We extend the basic theory of Andreev reflection (AR) in a normal metal/superconductor junction to the situation with an arbitrary time-dependent bias voltage V(t) across the junction. The central element of the theory is the fact that the Fourier transform of the AR amplitude has a casual structure. As an example, the theory is used to describe ...

Added: October 13, 2020

Akhmedov E., Popov F., Astrakhantsev N., Journal of High Energy Physics 2014 Vol. 1409 P. 071

We calculate one--loop corrections to the vertexes and propagators of photons and charged particles in the strong electric field backgrounds. We use the Schwinger--Keldysh diagrammatic technique. We observe that photon's Keldysh propagator receives growing with time infrared contribution. As the result, loop corrections are not suppressed in comparison with tree--level contribution. This effect substantially changes ...

Added: September 25, 2014

Arutyunov K., Лехтинен Я. С., Trefilov D. et al., Физика твердого тела 2021 Т. 63 № 9 С. 1233-1237

Utilization of of superconducting materials for new-generation nanoelectronic devices seems
extremely tempting because of the absence of energy dissipation during the electric current flow. However, in
small systems, the role of fluctuations can be highly important. In this study, the transport properties of thin
superconducting titanium nanoribbons have been experimentally and theoretically investigated. It has been
shown that quantum ...

Added: October 24, 2021

Bubis A. V., E. V. Shpagina, Nasibulin A. G. et al., Physical Review B: Condensed Matter and Materials Physics 2021 Vol. 104 No. 12 Article 125409

We investigate diffusive nanowire-based structures with two normal terminals on the sides and a central
superconducting island in the middle, which is either grounded or floating. Using a semiclassical calculation
we demonstrate that both device layouts permit a quantitative measurement of the energy dependent subgap
thermal conductance Gth from the spectral density of the current noise. In the ...

Added: April 3, 2023

Радкевич А., Semenov A. G., Zaikin A., Physical Review B: Condensed Matter and Materials Physics 2019 Vol. 100 No. 014520 P. 014520-1-014520-7

The quantum behavior of superconducting nanowires may essentially depend on the employed experimental setup. Here we investigate a setup that enables passing equilibrium supercurrent across an arbitrary segment of the wire without restricting fluctuations of its superconducting phase. The low temperature physics of the system is determined by a combined effect of collective soundlike plasma ...

Added: September 12, 2019

Shapiro Dmitriy S., Mirlin A., Shnirman A., Physical Review B: Condensed Matter and Materials Physics 2018 Vol. 98 No. 24 P. 245405-1-245405-12

We consider a Josephson contact mediated by 1D chiral modes on a surface of a 3D topological insulator with superimposed superconducting and magnetic layers. The system represents an interferometer in which 1D chiral Majorana modes on the boundaries of superconducting electrodes are linked by ballistic chiral Dirac channels. This model may be realized also in ...

Added: February 7, 2019

Андрияхина Е. С., Burmistrov I., Журнал экспериментальной и теоретической физики 2022 Т. 162 № 4 С. 522-540

The interplay of Anderson localization and electron-electron interactions is known to lead to enhancement of superconductivity due to multifractality of electron wave functions. We develop the theory of multifractally-enhanced superconducting states in two-dimensional systems in the presence of spin-orbit coupling. Using the Finkel'stein nonlinear sigma model, we derive the modified Usadel and gap equations that ...

Added: November 13, 2022

Gavrylenko P., Iorgov N., Lisovyy O., Journal of Physics A: Mathematical and Theoretical 2012 Vol. 45 No. 2 P. 025402

We study U(1) twist fields in a two-dimensional lattice theory of massive Dirac fermions. Factorized formulas for finite-lattice form factors of these fields are derived using elliptic parametrization of the spectral curve of the model, elliptic determinant identities and theta functional interpolation. We also investigate the thermodynamic and infinite-volume scaling limit, where the corresponding expressions ...

Added: October 20, 2014

Shapiro D. S., Pogosov W. V., Lozovik Y., Physical Review A: Atomic, Molecular, and Optical physics 2020 Vol. 102 No. 2 Article 023703

In view of recent proposals for the realization of anisotropic light-matter interaction in such platforms as (i) nonstationary or inductively and capacitively coupled superconducting qubits, (ii) atoms in crossed fields, and (iii) semiconductor heterostructures with spin-orbital interaction, the concept of a generalized Dicke model, where coupling strengths of rotating wave and counter-rotating wave terms are ...

Added: October 31, 2021

Stroganov P. L., Ya. V. Fominov, / Cornell University. Series cond-mat "arxiv.org". 2017. No. arXiv:1708.05089.

We consider ballistic SQUIDs with spin filtering inside half-metallic ferromagnetic arms. A singlet Cooper pair cannot pass through an arm in this case, so the Josephson current is entirely due to the Cooper pair splitting, with two electrons going to different interferometer arms. In order to elucidate the mechanisms of Josephson transport due to split ...

Added: October 18, 2017

Temu E., Lahteenmaki P., Golubev D. et al., Journal of Low Temperature Physics 2017 Vol. 189 P. 204-216

We have employed noise thermometry for investigations of thermal relaxation
between the electrons and the substrate in nanowires patterned from 40-nm-thick
titanium film on top of silicon wafers covered by a native oxide. By controlling the
electronic temperature Te by Joule heating at the base temperature of a dilution refrigerator,
we probe the electron–phonon coupling and the thermal boundary ...

Added: December 5, 2017

Denisov A., Bubis A., Piatrusha S. et al., Nanomaterials 2022 Vol. 12 No. 9 Article 1461

Mesoscopic superconductivity deals with various quasiparticle excitation modes, only one of them—the charge-mode—being directly accessible for conductance measurements due to the imbalance in populations of quasi-electron and quasihole excitation branches. Other modes carrying heat or even spin, valley etc. currents populate the branches equally and are charge-neutral, which makes them much harder to control. This ...

Added: April 3, 2023

M. : Faculty of Physics, MSU, 2017

The Low Temperature Physics Conference is an international event held every three years, under the auspices of the IUPAP through its Commission C5 on Low Temperature Physics. The aim of these conferences is to exchange information and views among the members of the international scientific community in the general field of Low Temperature Physics. It ...

Added: October 1, 2017

Arutyunov K., Уфа : Уфа: НИЦ «Аэтерна», 2020, 2020

Quantum fluctuations of the order parameter in quasi-1D-superconductors ...

Added: January 25, 2021

Ioselevich P., Chuklanov D. A., JETP Letters 2021 Vol. 113 P. 631-637

We consider a long diffusive Josephson junction where the weak link is a thin (normal metal (N)–ferromagnet (F)) bilayer (N and F form parallel links between superconductors (Ss)). We show that superconductivity in the weak link can be described by an effective one-dimensional Usadel equation containing a “diluted” exchange field as well as a weak ...

Added: October 25, 2021

Shein K., Zarudneva A., Emel’yanova V. et al., Physics of the Solid State 2020 Vol. 62 No. 9 P. 1539-1542

The transport properties of two types of quasi-one-dimensional superconducting microstructures were investigated at ultra-low temperatures: the narrow channels close-packed in the shape of meander, and the chains of tunneling contacts "superconductor-insulator-superconductor." Both types of the microstructures demonstrated high value of high-frequency impedance and-or the dynamic resistance. The study opens up potential for using of such ...

Added: September 18, 2020