arXiv subjects

Yu. M. Shukrinov

Publications and source records attributed to Yu. M. Shukrinov.

At least 19 recordsLinked to original sources

arXiv2026

Originality of resonance and locking phenomena in SFS $φ_0$ Josephson junction

We demonstrate the realization and interplay of two ferromagnetic resonances in one SFS $φ_0$ Josephson junction. First resonance that is realized under microwave radiation is the famous Kittel resonance. The other is Buzdin one appearing as a result of interaction of superconducting current and ferromagnetic interlayer magnetization. Transformations of one type of resonance to another under variation of external electromagnetic radiation and the $φ_0$ junction parameters open an interesting way to manipulation both of them. The combined ferromagnetic resonance that exhibits the features of both resonances is demonstrated too. The coupling of the Josephson phase with the magnetization of the ferromagnetic layer, caused by the spin-orbit interaction, leads to double synchronization, namely, synchronization of both magnetic precession and Josephson oscillations by external radiation. The obtained results demonstrate reach physics and unique opportunities for various applications.

cond-mat.supr-con↗

arXiv2025

Intrinsic space-time crystalline order in a hybrid Josephson junction

We demonstrate the emergence of an intrinsic space-time crystalline order in a long ferromagnetic $φ_{0}$ Josephson junction on a topological insulator without any external periodic modulation. The presence of the exchange and Dzyaloshinskii-Moriya interactions in a ferromagnetic layer with broken inversion symmetry internally modulates the critical current due to the coupling between the magnetic moment and the Josephson phase. This breaks the time translation symmetry, leading to the appearance of the space-time crystalline pattern in the spatiotemporal dependence of the in-plane current, which oscillates with almost twice the ferromagnetic resonance frequency. In the limit where the critical current is not modulated internally, the space-time crystalline order does not occur. In this case, only when an external parametric modulation is applied, the system exhibits a typical classical discrete space-time crystalline order that oscillates at half of the modulation frequency. Considering the still-pending problem of experimental detection, we demonstrate that a recently developed magnetometry device, which visualizes the supercurrent flow at the nanoscale, can be used to detect space-time crystalline patterns in hybrid Josephson junctions experimentally.

cond-mat.supr-con↗

arXiv2025

The uniqueness of the driven $φ_0$ Josephson junction: when steps are not Shapiro

The $φ_0$ superconductor-ferromagnet-superconductor Josephson junction exhibits unique locking phenomena under the external periodic signal when the magnetic component is taken into account. Contrary to the well-known Shapiro steps that come from the locking with the electric component, locking of the Josephson oscillations with the magnetic one results in the appearance of Buzdin steps in the current-voltage characteristic and a much more complex response of the system. These steps possess distinctive properties that are indications of their unique origins and locking mechanisms. The width of the Buzdin step oscillates with the amplitude of the magnetic component, nevertheless, it exhibits anomalies in the Bessel-like behavior. In addition, we perform an analytical analysis that supports the numerical results and shows that the width of the Buzdin step represents a product of two Bessel functions. Investigation of the effects that simultaneously appear in the magnetic subsystem reveals the presence of destructive interference and magnetization reorientation that accompany the appearance of Buzdin steps.

cond-mat.supr-con↗

arXiv2024

Resonant control of magnetization in a shunted $φ_0$ junction with LC circuit

The possibility of magnetization resonant control in a Josephson superconductor-ferromagnet-superconductor $φ_{0}$ junction shunted by an $LC$ circuit is demonstrated. As a result of the resonance of Josephson oscillations with oscillations in the circuit, a time-independent superconducting current arises in the junction. Due to the coupling of the Josephson phase and the magnetization of the ferromagnetic layer, the resulting superconducting current leads to a deviation of the easy axis from its initial position and to a precession of the magnetization around the tilted axis. We show that the tilt value increases with the increasing spin-orbit interaction and the Josephson to magnetic energy ratio. An analytical expression for the magnetization tilt is obtained, which agrees well with the results of numerical calculations. The emerging possibility of resonant control of magnetization in a shunted $φ_{0}$ junction can be used in the development of novel technologies in the field of superconducting electronics and spintronics.

cond-mat.supr-con↗

arXiv2024

Hysteresis and chaos in anomalous Josephson junctions without capacitance

Usually, overdamped Josephson junctions do not exhibit chaotic behavior in their phase dynamics, either because the phase space dimension is less than three (as in the case of a single overdamped ac-driven junction) or due to the general tendency of systems to become less chaotic with increasing dissipation (as in the case of coupled overdamped junctions). Here we consider the so-called $φ_0$ superconductor/ferromagnet/superconductor Josephson junction in which the current flowing through the junction may induce magnetization dynamics in the ferromagnetic interlayer. We find that due to the induced magnetization dynamics, even in the overdamped limit, i.e. for a junction without capacitance, the junction may exhibit chaos and hysteresis that in some cases leads to multiple branches in its current-voltage characteristics. We also show that pulsed current signals can be used to switch between the different voltage states, even in the presence of added thermal noise. Such switching could be used in cryogenic memory components.

cond-mat.supr-con↗

arXiv2024

Buzdin, Shapiro and Chimera Steps in $φ_0$ Josephson Junctions. II. Bifurcation, Switching, and Hysteresis

The dynamics of magnetization and current-voltage characteristics of the superconductor-ferromagnet-superconductor $φ_0$ Josephson junction in the presence of external electromagnetic radiation have been studied. Effects of radiation magnetic component are investigated in the frameworks of one- and two-signal models. The implementation of two types of dynamical states of magnetization is demonstrated. These states have a phase shift of $π$ in the synchronization region of magnetic precession and Josephson oscillations and differ in the nature of their time dependence. Transitions between these states with increasing and decreasing bias current show hysteresis, which is reflected in the bifurcation diagram and the current-voltage characteristics. We also provide an experimental way to test the obtained results by measuring the phase shift in voltage temporal dependence at fixed current value for both sweeping directions. The results obtained can find application in various fields of superconducting spintronics and quantum computing.

cond-mat.supr-con↗

arXiv2023

Thermal local quantum uncertainty in a two-qubit-superconducting system under decoherence

By considering the local quantum uncertainty (LQU) as a measure of quantum correlations, the thermal evolution of a two-qubit-superconducting system is investigated. We show that the thermal LQU can be increased by manipulating the Hamiltonian parameters such as the mutual coupling and Josephson energies, however, it undergoes sudden transitions at specific temperatures. Furthermore, a detailed analysis is presented regarding the impact of decohering channels on thermal LQU. This controllable LQU in engineering applications can disclose the advantage enabled in the superconducting charge qubits for designing quantum computers and quantum batteries.

quant-ph↗

arXiv2023

Buzdin, Shapiro and Chimera Steps in $φ_0$ Josephson Junctions

The unique resonance and locking phenomena in the superconductor-ferromagnet-superconductor $φ_0$ Josephson junction under external electromagnetic radiation are demonstrated when not just the electric but also the magnetic component of external radiation is taken into account. Due to the coupling of superconductivity and magnetism in this system, the magnetic moment precession of the ferromagnetic layer caused by the magnetic component of external radiation can lock the Josephson oscillations, which results in the appearance of a particular type of steps in the current-voltage characteristics, completely different from the well-known Shapiro steps. We call these steps the Buzdin steps in the case when the system is driven only by the magnetic component and the Chimera steps in the case when both magnetic and electric components are present. Unlike the Shapiro steps where the magnetization remains constant along the step, here it changes though the system is locked. The spin-orbit coupling substantially contributes to the amplitude, i.e., the size of these steps. Dramatic changes in their amplitudes are also observed at frequencies near the ferromagnetic resonance. Combinations of the Josephson and Kittel ferromagnetic resonances together with different types of locking pronounced in dynamics and current-voltage characteristics make the physics of this system very interesting and open up a series of new applications.

cond-mat.supr-con↗

arXiv2023

Resonance phenomena in a nanomagnet coupled to a Josephson junction under external periodic drive

We investigate resonance phenomena in a system consisting of a nanomagnet coupled to a Josephson junction under external periodic drive. The coupling in the system leads to appearance of additional resonance peaks whose properties depend on the periodic signal and Josephson junction dynamics. In the linear regime, we derive an analytical description of the resonance phenomena which is then confirmed by numerical simulations. This analytical method is universal and can be also applied to Josephson junctions with anomalous phase shift in current phase relation. This work provides a new method of controlling the resonances of hybrid structures, which may be interesting for applications.

cond-mat.supr-con↗

arXiv2022

Kapitsa pendulum effects in Josephson junction + nanomagnet under external periodic drive

We investigate reorientation effects under external periodic drive in the nanomagnet dynamics coupled to a Josephson junction. The Kapitsa pendulum is introduced as a mechanical analog to this system and we demonstrate the reorientation of the easy axis of the nanomagnet. The magnetic field generated by the Josephson junction and external drive plays the role of the oscillating force of the suspension point in the Kapitsa pendulum. The high frequency oscillations change the orientation of the magnetic moment. The magnetic field of the quasiparticle current determines the frequency dependence of the magnetic moment's orientation. We obtain simple analytical formulas for the stable position of the magnetic moment, both under the external periodic drive and without it. The influence of external periodic drive on the voltage of complete reorientation have been demonstrated.

cond-mat.other↗

arXiv2022

Locking of magnetization and Josephson oscillations at ferromagnetic resonance in $φ_0$ junction under external radiation

We demonstrate the locking by external electromagnetic radiation of magnetic precession in the $ φ_0 $ Josephson junction through Josephson oscillations in the region of ferromagnetic resonance. This leads to a step in the dependence of the magnetization on the bias current, the position of which is determined by the radiation frequency and the shape of the resonance curve. In junctions with a strong spin-orbit coupling, states with negative differential resistance appear on the IV-characteristic, resulting in an additional locking step. A detailed study of the time dependence of voltage and magnetization and their Fourier transforms shows that the corresponding oscillations have the same frequency as the oscillations at the first step, but they have a different amplitude and different dependence on the radiation frequency. This makes it possible to control not only the frequency, but also the amplitude of the magnetic precession in the locking region. It opens up unique perspectives for the control and manipulation of magnetic moment in hybrid systems such as anomalous Josephson junctions.

cond-mat.supr-con↗

arXiv2021

Bifurcation structure and chaos in nanomagnet coupled to Josephson junction

Recently an irregular easy axis reorientation demonstrating the Kapitza pendulum features were observed in numerical simulations of nanomagnet coupled to the Josephson junction. To explain its origin we study the magnetization bifurcations and chaos which appear in this system due to interplay of superconductivity and magnetism. The bifurcation structure of the magnetization under the variation of Josephson to magnetic energy ratio as a control parameter demonstrates several precessional motions. They are related to chaotic behavior, bistability, and multiperiodic orbits in the ferromagnetic resonance region. Effect of external periodic drive on the bifurcation structure is investigated. The results demonstrate high-frequency modes of periodic motion and chaotic response near resonance. Far from the ferromagnetic resonance we observe a quasiperiodic behavior.

cond-mat.supr-con↗

arXiv2021

Anomalous Gilbert Damping and Duffing Features of the SFS {\boldmath $φ_0$} Josephson Junction

We demonstrate unusual features of phase dynamics, IV-characteristics and magnetization dynamics of the $φ_0$ Josephson junction at small values of spin-orbit interaction, ratio of Josephson to magnetic energy and Gilbert damping. In particular, an anomalous shift of the ferromagnetic resonance frequency with an increase of Gilbert damping is found. The ferromagnetic resonance curves show the Duffing oscillator behaviour, reflecting the nonlinear nature of Landau-Lifshitz-Gilbert (LLG) equation. Based on the numerical analysis of each term in LLG equation we obtained an approximated equation demonstrated both damping effect and Duffing oscillator features. The resulting Duffing equation incorporates the Gilbert damping in a special way across the dissipative term and the restoring force. A resonance method for the determination of spin-orbit interaction in noncentrosymmetric materials which play the role of barrier in $φ_0$ junctions is proposed.

cond-mat.supr-con↗

arXiv2020

Magnetization reversal in S/F/S Josephson junctions on a 3D topological insulator

We study a magnetization reversal by an electric current pulse in a superconductor/insulating ferromagnet/superconductor Josephson junction placed on top of a 3D topological insulator. It is demonstrated that such a system is perspective for low-dissipative spintronics because of the strong spin-momentum locking in the TI surface states. This property provides an ideally strong coupling between the orbital and spin degrees of freedom thus giving a possibility of efficient reversal of the magnetic moment by current pulse with amplitude lower than the critical current, that results in strongly reduced energy dissipation. The underlying physical mechanism of the reversal is discussed. The influence of the magnetic anisotropy on the controllability of the reversal by the pulse duration is investigated. In addition, a way of a simultaneous electrical detection of the reversal is proposed.

cond-mat.supr-con↗

arXiv2020

Analytical criteria for magnetization reversal in $φ_0$ Josephson junction

The $φ_0$ Josephson junctions formed by ordinary superconductors and a magnetic non-centrosymmetric interlayer are studied. We derive an analytical solution for the magnetization dynamics induced by an arbitrary current pulse and formulate the criteria for magnetization reversal. Using the obtained results, the form and duration of the current pulse are optimized. The agreement between analytical and numerical investigations is reached in the case of a large product of the ratio Josephson to magnetic energy, strength of spin-orbit interaction and a minimal value of the current pulse. The obtained results allow one to predict magnetization reversal at the chosen system parameters.

cond-mat.supr-con↗

arXiv2019

Josephson current between two $p$-wave superconducting nanowires in the presence of Rashba spin-orbit interaction and Zeeman magnetic fields

Josephson current between two one-dimensional nanowires with proximity induced $p$-wave superconducting pairing is calculated in the presence of Rashba spin-orbit interaction, in-plane and normal magnetic fields. We show that Andreev retro-tunneling is realized by means of three channels. The main contribution to the Josephson current gives a scattering in a conventional particle-hole channel, when an electron-like quasiparticle reflects to a hole-like quasiparticle with opposite spin yielding a current which depends only on the order parameters' phase differences $φ$ and oscillates with $4π$ period. Second anomalous particle-hole channel, corresponding to the Andreev reflection of an incident electron-like quasiparticle to an hole-like quasiparticle with the same spin orientation, survives only in the presence of the in-plane magnetic field. The contribution of this channel to the Josephson current oscillates with $4π$ period not only with $φ$ but also with orientational angle of the in-plane magnetic field $θ$ resulting in a magneto-Josephson effect. Third anomalous particle-particle channel, which represents a reflection of an electron-like (hole-like) quasiparticle to a electron-like (hole-like) quasiparticle with opposite spin-orientation, oscillates only with the in-plane magnetic field orientation angle $θ$. We present a detailed theoretical analysis of both DC and AC Josephson effects in such a system showing contributions from all these channels and discuss experiments which can test our theory.

cond-mat.supr-con↗

arXiv2019

The ac Driven Annular Josephson Junctions: The Missing Steps

Examination of an annular system of underdamped Josephson junctions in the presence of external radiation showed that the ability of the system to lock with some external radiation was determined not only by the number but also by the type of rotating excitations (fluxons or antifluxons). Shapiro steps can be observed in the current-voltage characteristics only in the system with trapped fluxons or in the system with fluxon-antifluxon pairs. If the trapped fluxons circulate simultaneously with fluxon-antifluxon pairs, there are no Shapiro steps regardless of the amplitude or frequency of the applied external radiation.

cond-mat.supr-con↗

arXiv2019

Resonance phenomena in the annular array of underdamped Josephson junctions

Appearance and origin of resonance phenomena have been studied in the annular system of underdamped Josephson junctions. If no fluxon is trapped in the system, dynamics is governed by the motion of fluxon-antifluxon pairs, while if trapped fluxons are present, they can move solely but also simultaneously with the pairs. Locking between the rotating excitations (fluxons and antifluxons) and the Josephson frequency leads to the appearance of zero field steps in the current-voltage characteristics, which can further exhibit branching due to resonance between the rotating excitations and plasma oscillations in their tale. The number of zero field steps and their branching are strongly determined by the total number of excitations present in the system. High resolution analysis further reveals not only some interesting properties of zero field steps, but also shows that the current-voltage characteristics is determined not only by the number, but also by the type of excitations, i.e., whether the dynamics is governed only by the motion of fluxon-antifluxon pairs or the trapped fluxons, or they move simultaneously in the system.

cond-mat.supr-con↗