Moscow Region, Russia
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Shukrinov Y.M.,BLTP | Gaafar M.A.,Menoufia University
Physical Review B - Condensed Matter and Materials Physics | Year: 2011

A manifestation of a resonance-type hysteresis related to the parametric resonance in the system of coupled Josephson junctions is demonstrated. In contrast with the McCumber and Steward hysteresis, we find that the width of this hysteresis is inversely proportional to the McCumber parameter and it also depends on the coupling between junctions and the boundary conditions. Investigation of the time dependence of the electric charge in superconducting layers allows us to explain the origin of this hysteresis by different charge dynamics for increasing and decreasing bias current processes. The effect of the wavelength of the longitudinal plasma wave created at the resonance on the charging of superconducting layers is demonstrated. We find a strong effect of the dissipation in the system on the amplitude of the charge oscillations at the resonance. © 2011 American Physical Society.


Mandal S.,Institute of Physics, Bhubaneswar | Maiti M.,BLTP | Varma V.K.,Abdus Salam International Center For Theoretical Physics
Physical Review B - Condensed Matter and Materials Physics | Year: 2016

We investigate the von Neumann entanglement entropy and Schmidt gap in the vortex-free ground state of the Kitaev model on the honeycomb lattice for square/rectangular and cylindrical subsystems. We find that, for both the subsystems, the free-fermionic contribution to the entanglement entropy SE exhibits signatures of the phase transitions between the gapless and gapped phases. However, within the gapless phase, we find that SE does not show an expected monotonic behavior as a function of the coupling Jz between the suitably defined one-dimensional chains for either geometry; moreover, the system generically reaches a point of minimum entanglement within the gapless phase before the entanglement saturates or increases again until the gapped phase is reached. This may be attributed to the onset of gapless modes in the bulk spectrum and the competition between the correlation functions along various bonds. In the gapped phase, on the other hand, SE always monotonically varies with Jz independent of the subregion size or shape. Finally, further confirming the Li-Haldane conjecture, we find that the Schmidt gap Δ defined from the entanglement spectrum also signals the topological transitions but only if there are corresponding zero-energy Majorana edge states that simultaneously appear or disappear across the transitions. We analytically corroborate some of our results on entanglement entropy, the Schmidt gap, and the bulk-edge correspondence using perturbation theory. © 2016 American Physical Society.


Kazakov D.I.,BLTP
Nuclear Physics B - Proceedings Supplements | Year: 2010

Supersymmetry, a new symmetry that relates bosons and fermions in particle physics, still escapes observation. Search for SUSY is one of the main aims of the recently launched Large Hadron Collider. The other possible manifestation of SUSY is the Dark Matter in the Universe. The present lectures contain a brief introduction to supersymmetry in particle physics. The main notions of supersymmetry are introduced. The supersymmetric extension of the Standard Model - the Minimal Supersymmetric Standard Model - is considered in more detail. Phenomenological features of the MSSM as well as possible experimental signatures of SUSY at the LHC are described. The DM problem and its possible SUSY solution is presented. © 2010 Elsevier B.V.


Shukrinov Y.M.,BLTP | Hamdipour M.,Institute for Advanced Studies in Basic Sciences | Kolahchi M.R.,Institute for Advanced Studies in Basic Sciences | Botha A.E.,University of South Africa | Suzuki M.,Kyoto University
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2012

Manifestation of chaos in the temporal dependence of the electric charge is demonstrated through the calculation of the maximal Lyapunov exponent, phase-charge and charge-charge Lissajous diagrams and correlation functions. It is found that the number of junctions in the stack strongly influences the fine structure in the current-voltage characteristics and a strong proximity effect results from the nonperiodic boundary conditions. The observed resonance-related chaos exhibits intermittency. The criteria for a breakpoint region with no chaos are obtained. Such criteria could clarify recent experimental observations of variations in the power output from intrinsic Josephson junctions in high temperature superconductors. © 2012 Elsevier B.V.


Shnir Y.M.,BLTP
Physics of Particles and Nuclei Letters | Year: 2015

We discuss a U(1) gauged version of the 2+1 dimensional planar Skyrme model supplemented by the Maxwell term. We show that there exist variety of static multi-soliton configurations coupled to the noninteger fluxes of magnetic field, which revert to the usual planar Skyrmions in the limit of the gauge coupling constant vanishing. The structure of the multisoliton solutions of the model strongly depends on the particular choice of the potential term which may break the rotational invariance. We investigate the dependency of the shapes, masses and magnetic fluxes of the gauged planar Skyrmions with broken symmetry on the gauge coupling constant. We further find that in the strong coupling limit the magnetic fluxes associated with the parton components of the solitons became quantized in fractional units of topological charge. © 2015, Pleiades Publishing, Ltd.


Neutron spectra from the low-energy K - + d → π + Σ + n reaction were calculated. This quantity should carry information on the Λ(1405) resonance. We checked the possibility of extracting this information. © 2012 Springer Science+Business Media B.V.


Teryaev O.V.,BLTP
Nuclear Physics B - Proceedings Supplements | Year: 2011

The new manifestations of Axial Anomaly (AA) are considered. The generalization of dispersive approach to AA and its applications to hadronic physics are outlined. The couplings of quark currents to magnetic fields and vorticity generated in heavy-ion collisions are also discussed. © 2011.


Mikhailov V.A.,Samara State Aerospace University | Troshkin N.V.,Samara State Aerospace University | Trunin A.M.,BLTP
Progress in Biomedical Optics and Imaging - Proceedings of SPIE | Year: 2016

The relaxation of a pair of dipole-dipole interacting two-level atoms with parallel dipole moments in a large dissipative system is studied on the basis of the generalized coherent states method. The Fokker-Planck equation and its exact solution are obtained. Explicit formulas for two-time correlation functions are given. The influence of the magnitude of the interaction on the shape of the radiation line is investigated. © 2016 SPIE.


Shukrinov Y.M.,BLTP | Botha A.E.,University of South Africa | Medvedeva S.Y.,Moscow Institute of Physics and Technology | Kolahchi M.R.,Institute for Advanced Studies in Basic Sciences | Irie A.,Utsunomiya University
Chaos | Year: 2014

The phase dynamics of Josephson junctions (JJs) under external electromagnetic radiation is studied through numerical simulations. Current-voltage characteristics, Lyapunov exponents, and Poincaré sections are analyzed in detail. It is found that the subharmonic Shapiro steps at certain parameters are separated by structured chaotic windows. By performing a linear regression on the linear part of the data, a fractal dimension of D = 0.868 is obtained, with an uncertainty of ±0.012. The chaotic regions exhibit scaling similarity, and it is shown that the devil's staircase of the system can form a backbone that unifies and explains the highly correlated and structured chaotic behavior. These features suggest a system possessing multiple complete devil's staircases. The onset of chaos for subharmonic steps occurs through the Feigenbaum period doubling scenario. Universality in the sequence of periodic windows is also demonstrated. Finally, the influence of the radiation and JJ parameters on the structured chaos is investigated, and it is concluded that the structured chaos is a stable formation over a wide range of parameter values. © 2014 AIP Publishing LLC.


Shukrinov Yu.M.,BLTP | Medvedeva S.Yu.,Moscow Institute of Physics and Technology | Botha A.E.,University of South Africa | Kolahchi M.R.,Institute for Advanced Studies in Basic Sciences | Irie A.,Utsunomiya University
Physical Review B - Condensed Matter and Materials Physics | Year: 2013

Detailed numerical simulations of the IV characteristics of a Josephson junction under external electromagnetic radiation show the devil's staircase within different bias current intervals. We have found that the observed steps form very precisely continued fractions. Increase of the amplitude of the radiation shifts the devil's staircase to higher Shapiro steps. An algorithm for the appearance and detection of subharmonics with increasing radiation amplitude is proposed. We demonstrate that the subharmonic steps registered in the well-known experiments by Dayem and Wiegand [Phys. Rev. 155, 419 (1967)10.1103/PhysRev.155.419] and Clarke [Phys. Rev. B 4, 2963 (1971)10.1103/PhysRevB.4.2963] also form continued fractions. © 2013 American Physical Society.

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