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Publisher's version (útgefin grein), The two-dimensional Heisenberg exchange model with out-of-plane anisotropy and a Dzyaloshinskii-Moriya interaction is employed to investigate the lifetime and stability of antiferromagnetic (AFM) skyrmion as a function of temperature and external magnetic field. An isolated AFM skyrmion is metastable at zero temperature in a certain parameter range set by two boundaries separating the skyrmion state from the uniform AFM phase and a stripe domain phase. The distribution of the energy barriers for the AFM skyrmion decay into the uniform AFM state complements the zero-temperature stability diagram and demonstrates that the skyrmion stability region is significantly narrowed at finite temperatures. We show that the AFM skyrmion stability can be enhanced by an application of magnetic field, whose strength is comparable to the spin-flop field. This stabilization of AFM skyrmions in external magnetic fields is in sharp contrast to the behavior of their ferromagnetic counterparts. Furthermore, we demonstrate that the AFM skyrmions are stable on the timescales of milliseconds below 50 K for realistic material parameters, making it feasible to observe them in modern experiments., P.F.B. acknowledges support from the Icelandic Research Fund (Grant No. 163048-052), the University of Iceland Research Fund, and Alexander von Humboldt Foundation. P.F.B., D.Y., D.R.G., and M.T. acknowledge support from the Russian Science Foundation under Project No. 17-12-01359. The work of M.T. was partially supported by ICC-IMR, Tohoku University (Japan). O.A.T. acknowledges support by a grant of the Center for Science and Innovation in Spintronics (Core Research Cluster), Tohoku University, by Ministry of Science and Higher Education of the Russian Federation in the framework of Increase Competitiveness Program of NUST “MISi” (No. K2-2019-006), implemented by a governmental decree dated 16th of March 2013, N 211, and by JSPS and RFBR under the Japan-Russia Research Cooperative Program.

We consider the ground state of an electron gas embedded in a quantum gyrotropic cavity. We show that the light-matter interaction leads to a nontrivial topology of the many-body electron-photon wave function characterized by a nonzero Berry curvature. Physically, the latter manifests as the anomalous Hall effect, appearance of equilibrium edge/surface currents and orbital magnetization induced by vacuum fluctuations. Remarkably, closed analytical expressions for the anomalous Hall conductivity and macroscopic magnetization are obtained for the interacting many-body case.

Second-harmonic generation (SHG) is a well-known nonlinear spectroscopy method to probe electronic structure, specifically, in transition metal dichalcogenide (TMDC) monolayers. This work investigates the nonlinear dynamics of a strongly excited TMDC monolayer by solving the time evolution equations for the density matrix. It is shown that the presence of excitons qualitatively changes the nonlinear dynamics leading, in particular, to a huge enhancement of the nonlinear signal as a function of the dielectric environment. It is also shown that the SHG polarization angular diagram and its dependence on the driving strength are very sensitive to the type of exciton state. This sensitivity suggests that SHG spectroscopy is a convenient tool for analyzing the fine structure of excitonic states., Comment: 13 pages, 5 figures

We demonstrate that the temperature and doping dependencies of the photoluminescence (PL) spectra of a doped MoS

Optical spectra of two-dimensional transition-metal dichalcogenides (TMDC) are influenced by complex multiparticle excitonic states. Their theoretical analysis requires solving the many-body problem, which in most cases, is prohibitively complicated. In this work, we calculate the optical spectra by exact diagonalization of the three-particle Hamiltonian within the Tamm-Dancoff approximation where the doping effects are accounted for via the Pauli blocking mechanism, modelled by a discretized mesh in the momentum space. The single-particle basis is extracted from the ab initio calculations. Obtained three-particle eigenstates and the corresponding transition dipole matrix elements are used to calculate the linear absorption spectra as a function of the doping level. Results for negatively doped ${\mathrm{MoS}}_{2}$ monolayer (ML) are in excellent quantitative agreement with the available experimental data, validating our approach. The results predict additional spectral features due to the intervalley exciton that is optically dark in an undoped ML but is brightened by the doping. Our approach can be applied to a plethora of other atomically thin semiconductors, where the doping induced brightening of the many-particle states is also anticipated.

We propose a computationally efficient approach to account for the nonadiabatic effects in time-dependent density functional theory (TDDFT) based on a representation of the frequency-dependent exchange-correlation kernel as a response of a set of damped oscillators. The requirements to computational resources needed to implement our approach do not differ from those of the standard real-time TDDFT in the adiabatic local density approximation. Thus, our result offers an exciting opportunity to take into account temporal nonlocality and memory effects in calculations with TDDFT in quantum chemistry and solid state physics for unprecedentedly low costs.

In this paper, bound excitons are studied in the frame work of the time-dependent density-functional theory (TDDFT). Two 1D systems are considered: the Kronig–Penney model and a smooth periodic potential. Within the two-band approximation, we study the dependence of the number of bound excitons on the type of exchange-correlation kernels. Two simple approximations are used: the short-ranged contact xc kernel and the long-ranged (or ‘soft-Coulomb’) one. As a result, one or two bound ecxitons are produced, depending on the system.

We observe a broadband chaotic signal of Terahertz frequency emitted from a superconducting junction. The generated radiation has a wide spectrum reaching 0.7 THz and power sufficient to drive on-chip circuit elements. To our knowledge, this is the first experimental observation of a high-frequency chaotic signal emitted by a superconducting system which lies inside the Terahertz gap. Our experimental finding is fully confirmed by the numerical modeling based on the microscopic theory and reveals the unrealized potential of superconducting systems in chaos-based Terahertz communication, fast generation of true random numbers and non-invasive Terahertz spectroscopy applicable to physical, chemical and biological systems., 6 pages, 3 figures

We demonstrate that the temperature and doping dependencies of the photoluminescence (PL) spectra of a doped MoS2 monolayer have several peculiar characteristics defined by trion radiative decay. While only zero-momentum exciton states are coupled to light, radiative recombination of non-zero momentum trions is also allowed. This leads to an asymmetric broadening of the trion spectral peak and redshift of the emitted light with increasing temperature. The lowest energy trion state is dark, which is manifested by the sharply non-monotonic temperature dependence of the PL intensity. Our calculations combine the Dirac model for the single-particle states, the parameters for which are obtained from the first principle calculations, and the direct solution of the three-particle problem within the Tamm-Dancoff approximation. The numerical results are well captured by a simple model that yields analytical expressions for the temperature dependencies of the PL spectra., Comment: 10 pages, 6 figures

We consider theoretically one-dimensional polariton ring accounting for both longitudinal-transverse (TE-TM) and Zeeman splitting of spinor polariton states and spin dependent polariton-polariton interactions. We present the novel class of solutions in the form of the localized defects rotating with constant angular velocity and analyze their properties for realistic values of the parameters of the system. We show that the effects of the geometric phase arising from the interplay between external magnetic field and TE-TM splitting introduce chirality in the system and make solitons propagating in clockwise and anticlockwise directions non equivalent. This can be interpreted as solitonic analog of Aharonov-Bohm effect., several minor revisions made

We study exciton polaritons in a two-dimensional Lieb lattice of micropillars. The energy spectrum of the system features two flat bands formed from S and P x , y photonic orbitals, into which we trigger bosonic condensation under high power excitation. The symmetry of the orbital wave functions combined with photonic spin-orbit coupling gives rise to emission patterns with pseudospin texture in the flat band condensates. Our Letter shows the potential of polariton lattices for emulating flat band Hamiltonians with spin-orbit coupling, orbital degrees of freedom, and interactions., The work was supported by EPSRC Grant No. EP/ N031776/1, ERC Advanced Grant EXCIPOL No. 320570 and Megagrant No. 14.Y26.31.0015. D. R. G. and I. V. I. acknowledge support from Project No. 3.8884.2017/8.9 of the Ministry of Education and Science of the Russian Federation. I. A. S. acknowledges support from Project No. 3.2614.2017 of the Ministry of Education and Science of the Russian Federation and Rannis Project No. 163082-051.

Since the very first experimental realization of Josephson flux-flow oscillator (FFO), its theoretical description has been limited by the phenomenological per- turbed sine-Gordon equation (PSGE). While PSGE can qualitatively describe the topological excitations in Josephson junctions that are sine-Gordon solitons or flux- ons, it is unable to capture essential physical phenomena of a realistic system such as the coupling between tunnel currents and electromagnetic radiation. Furthermore, PSGE neglects any dependence on energy gaps of superconductors and makes no distinction between symmetric and asymmetric junctions: those made of two iden- tical or two different superconducting materials. It was not until recently when it became possible to calculate properties of FFO by taking into account information about energy gaps of superconductors [D. R. Gulevich et al., Phys. Rev. B 96, 024215 (2017)]. Such approach is based on the microscopic tunneling theory and has been shown to describe essential features of symmetric Nb-AlOx-Nb junctions. Here we extend this approach to asymmetric Nb-AlN-NbN junctions and compare the calculated current-voltage characteristics to our experimental results., Comment: 15 pages, 3 figures

MiTMoJCo (Microscopic Tunneling Model for Josephson Contacts) is C code which aims to assist modeling of superconducting Josephson contacts based on the microscopic tunneling theory. The code offers implementation of a computationally demanding part of this calculation, that is evaluation of superconducting pair and quasiparticle tunnel currents from the given tunnel current amplitudes (TCAs) which characterize the junction material. MiTMoJCo comes with a library of pre-calculated TCAs for frequently used Nb-AlOx-Nb and Nb-AlN-NbN junctions, a Python module for developing custom TCAs, supplementary optimum filtration module for extraction of a constant component of a sinusoidal signal and examples of modeling few common cases of superconducting Josephson contacts., Comment: 7 pages, 1 figure, 1 table

Exploring the properties of strongly correlated systems through quantum simulation with photons, cold atoms or polaritons represents an active area of research. In fact, the latter permits to shed the light on the behavior of complex systems which are hardly to be addressed in the laboratory or tackled numerically. In this study we discuss an analogue of graphene formed by exciton-polariton spin vortices arranged into a hexagonal lattice. We show how the graphene-type dispersion at different energy scales arises for several types of exciton-polariton spin vortices. In contrast to previous studies of exciton-polaritons in artificial lattices, the use of exciton-polariton spin vortex modes offers a more rich playground for quantum simulations. In particular, we demonstrate that the sign of the nearest neighbor coupling strength can be inverted., 5 pages, 2 figures

We elaborate a theoretical description of large Josephson junctions which is based on the Werthamer's microscopic tunneling theory. The model naturally incorporates coupling of electromagnetic radiation to the tunnel currents and, therefore, is particularly suitable for description of the self-coupling effect in Josephson junction. In our numerical calculations we treat the arising integro-differential equation, which describes temporal evolution of the superconducting phase difference coupled to the electromagnetic field, by the Odintsov-Semenov-Zorin algorithm. This allows us to avoid evaluation of the time integrals at each time step while taking into account all the memory effects. To validate the obtained microscopic model of large Josephson junction we focus our attention on the Josephson flux flow oscillator. The proposed microscopic model of flux flow oscillator does not involve the phenomenological damping parameter, rather, the damping is taken into account naturally in the tunnel current amplitudes calculated at a given temperature. The theoretically calculated current-voltage characteristics is compared to our experimental results obtained for a set of fabricated flux flow oscillators of different lengths. Our theoretical calculation agrees well with the obtained experimental results, and, to our knowledge, is the first where theoretical description of Josephson flux flow oscillator is brought beyond the perturbed sine-Gordon equation., Comment: 13 pages, 2 figures

Matter in nontrivial topological phase possesses unique properties, such as support of unidirectional edge modes on its interface. It is the existence of such modes which is responsible for the wonderful properties of a topological insulator – material which is insulating in the bulk but conducting on its surface, along with many of its recently proposed photonic and polaritonic analogues. We show that exciton-polariton fluid in a nontrivial topological phase in kagome lattice, supports nonlinear excitations in the form of solitons built up from wavepackets of topological edge modes – topological edge solitons. Our theoretical and numerical results indicate the appearance of bright, dark and grey solitons dwelling in the vicinity of the boundary of a lattice strip. In a parabolic region of the dispersion the solitons can be described by envelope functions satisfying the nonlinear Schrödinger equation. Upon collision, multiple topological edge solitons emerge undistorted, which proves them to be true solitons as opposed to solitary waves for which such requirement is waived. Importantly, kagome lattice supports topological edge mode with zero group velocity unlike other types of truncated lattices. This gives a finer control over soliton velocity which can take both positive and negative values depending on the choice of forming it topological edge modes., Ministry of Education and Science of Russian Federation 3.8884.2017 3.1365.2017 RFBR project 16-32-60040 mol-a-dx 16-32-60123 Rannis projects 141241-051 163082-051 ITMO University through the grant of the Government of the Russian Federation 074-U01 Ministry of Education 14.Y26.31.0015

An external off-resonant pumping is proposed as a tool to control the Dzyaloshinskii-Moriya interaction (DMI) in ferromagnetic layers with strong spin-orbit coupling. Combining theoretical analysis with numerical simulations for an $s$-$d$-like model we demonstrate that linearly polarized off-resonant light may help stabilizing novel noncollinear magnetic phases by inducing a strong anisotropy of the DMI. We also investigate how with the application of electromagnetic pumping one can control the stability, shape and size of individual skyrmions to make them suitable for potential applications., 9 pages, 3 figures

We present experimental and theoretical results for T-junction flux flow oscillator in which the flow of Josephson fluxons is subjected to the influence of a T-junction. Our experimental results indicate a broad spectrum of the ac electric field generated by such oscillator. Our numerical calculations with the use of microscopic tunneling theory confirm this conclusion and suggest a chaotic dynamics in most of its current-voltage characteristics.

We address the electromagnetic properties of two-dimensional electron gas confined by a dielectric environment in the presence of both Rashba and Dresselhaus spin-orbit interactions. It is demonstrated that off-diagonal components of the conductivity tensor resulting from a delicate interplay between Rashba and Dresselhaus couplings lead to the hybridization of transverse electric and transverse magnetic surface electromagnetic modes localized at the interface. We show that the characteristics of these hybrid surface waves can be controlled by additional intense external off-resonant coherent pumping., Comment: 6 pages, 2 figures

Post-print (lokagerð höfunda), We study discrete nonlinear edge excitations of polaritonic kagome lattice. We show that when nontrivial topological phase of polaritons is realized, the kagome lattice permits propagation of bright solitons formed from topological edge states., D.R.G., D.Y. and I.V.I. acknowledge support from the grant 3.8884.2017 of the Ministry of Ed- ucation and Science of the Russian Federation. D.Y. acknowledges support from RFBR project 16-32-60040. I.A.S. acknowledge support from the Icelandic Research Fund, Grant No. 163082-051, mega-grant 14.Y26.31.0015 of the Ministry of Education and Science of the Russian Federation and Horizon2020 RISE project CoExAN, Grant No. 644076.

We study a system of microcavity pillars arranged into a kagome lattice. We show that polarization-dependent tunnel coupling of microcavity pillars leads to the emergence of the effective spin-orbit interaction consisting of the Dresselhaus and Rashba terms, similar to the case of polaritonic graphene studied earlier. Appearance of the effective spin-orbit interaction combined with the time-reversal symmetry-breaking resulting from the application of the magnetic field leads to the nontrivial topological properties of the Bloch bundles of polaritonic wavefunction. These are manifested in opening of the gap in the band structure and topological edge states localized on the boundary. Such states are analogs of the edge states arising in topological insulators. Our study of polarization properties of the edge states clearly demonstrate that opening of the gap is associated with the band inversion in the region of the Dirac points of the Brillouin zone where the two bands corresponding to polaritons of opposite polarizations meet. For one particular type of boundary we observe a highly nonlinear energy dispersion of the edge state which makes polaritonic kagome lattice a promising system for observation of edge state solitons., 7 pages, 4 figures

Quantum tunneling of vortices had been found to be an important novel phenomena for description of low temperature creep in high temperature superconductors (HTSCs). We speculate that quantum tunneling may be also exhibited in mesoscopic superconductors due to vortices trapped by the Bean-Livingston barrier. The London approximation and method of images is used to estimate the shape of the potential well in superconducting HTSC quantum dot. To calculate the escape rate we use the instanton technique. We model the vortex by a quantum particle tunneling from a two-dimensional ground state under magnetic field applied in the transverse direction. The resulting decay rates obtained by the instanton approach and conventional WKB are compared revealing complete coincidence with each other.

We propose a device able to generate trains of Josephson fluxons without application of external magnetic field – fluxon pump. The pulses of individual fluxons are generated by cloning single fluxons trapped inside a reservoir. When an electric current is applied, a flow of fluxons is generated in the long attachment connected to the reservoir of fluxons. The role of a reservoir is played by Josephson junctions in the form of a loop where one or several fluxons are permanently trapped.

We study the nucleation of vortices in a thin mesoscopic superconducting disk in an applied magnetic field perpendicular to the disc. We write down an expression for the free energy of the system with an arbitrary number of vortices and anti-vortices. For a given applied field, we minimize the free energy to find the optimal position of the vortices and anti-vortices. We also calculate the magnetization of the disk as a function of the applied field and hence the determine the different configurations possible in which a fixed number of fluxoids can penetrate the disk.

We describe new phenomena arising in long and extended Josephson junctions associated with the two-dimensional character of these junctions. A vortex in such junctions has additional degrees of freedom related to its length. We investigate the behaviour of a Josephson vortex in curved waveguides. As a result we have proposed how to increase transmission properties of a curved waveguide. Moreover, there may arise a flux cloning phenomenon. In this phenomenon the vortex may split into two or more new vortices at the special T, Y or any multiple shaped junction. We describe a series of new devices, the operation of which is based on flux cloning.

We analyze the switching to resistive state of an annular Josephson junction due to thermal activation. Mostly, we concentrate on moderate length junctions with a circumference about 10 λ J . Using a simple approximation the switching current distribution is analyzed and its standard deviation is analytically calculated. We show that the switching of the annular Josephson junction observed in recent experiments can be interpreted as a nearly homogeneous phase switching in the form of a classical string escape. Thus, in the regime close to the critical bias current, the behavior of the AJJ is similar to a small Josephson junction. Also, the deviation of the standard deviation from a T 2/3 power low and possible observation of the vortex–antivortex pair annihilation are discussed.

It has been suggested that superheavy charged particles might have been born in primordial bound pairs at the end of cosmic inflation. Such pairs have been proposed as a source of ultrahigh energy cosmic rays (UHECR). We show that primordial bound pairs of magnetic monopoles larger than 10-9 cm quickly thermalise due to the interaction with primordial electron–positron plasma and any such initial primordial concentration is washed out. The final concentration will therefore be defined by their equilibrium abundance.

We propose a method of resolving a spatially coherent signal, which contains on average just a single photon, against the background of local noise at the same frequency. The method is based on detecting the signal simultaneously in several points more than a wavelength apart through the entangling interaction of the incoming photon with the quantum metamaterial sensor array. The interaction produces the spatially correlated quantum state of the sensor array, characterised by a collective observable (e.g., total magnetic moment), which is read out using a quantum nondemolition measurement. We show that the effects of local noise (e.g., fluctuations affecting the elements of the array) are suppressed relative to the signal from the spatially coherent field of the incoming photon as ~1√N, where N is the number of array elements. The realisation of this approach in the microwave range would be especially useful and is within the reach of current experimental techniques.

We describe a method of controlled creation and detection of breathers in long Josephson Junctions. We show how a breather can be detected and investigated by measuring switching of the current biased Josephson junction to a resistive state. The complete theoretical description of the switching events associated with the decay of a breather into a fluxon-antifluxon pair is developed. Eventually, we propose several designs of the systems where breathers can be observed.

In present paper we have developed a new device, Flux-Flow Oscillator (FFO) where flux cloning phenomena have been demonstrated. Such FFO made with the use of flux cloning circuit can in principle operate even without magnetic field, that is in a very different manner than conventional FFO [1] developed nowadays for practical applications [2, 3]. We have designed such a novel device and build it up with the use of the long Josephson T-shaped junction of a linear overlap geometry made up with Nb-AlO x -Nb technology. We have theoretically described the properties of such a device and the dynamics of vortices there. These theoretical studies have been performed in the framework of a sine-Gordon model, which includes surface losses. Finally we have tested the device experimentally and demonstrated that the flux cloning can lead to a strong coherent terahertz radiation. There the shape of the spectral lines and the current-voltage characteristics have been also measured.

We analytically study the excitation of surface Josephson plasma waves (SJPWs) propagating across the junctions in layered superconductors in the presence of external dc magnetic field. Both the attenuated total reflection and the modulation of the superconducting parameters methods of the SJPWs excitation are considered. We show that the reflection of the incident electromagnetic wave can be substantially decreased due to the resonance excitation of SJPWs, for certain angles and frequencies of the incident wave when changing the magnetic field. Moreover, we find physical conditions guaranteeing the total suppression of the specular reflectivity. The analytical results are supported by the numerical simulations.

We predict a class of excitations propagating along a Josephson vortex in two-dimensional Josephson junctions. These excitations are associated with the distortion of a Josephson vortex line of an arbitrary profile. We derive a universal analytical expression for the energy of arbitrary-shape excitations, investigate their influence on the dynamics of a vortex line, and discuss conditions where such excitations can be created. Finally, we show that such excitations play the role of a clock for a relativistically-moving Josephson vortex and suggest an experiment to measure a time-dilation effect analogous to that in special relativity. The position of the shape excitation on a Josephson vortex acts like a ``minute hand'' showing the time in the rest frame associated with the vortex. Remarkably, at some conditions, the shape wave can carry negative energy: a vortex with the shape excitation can have less energy than the same vortex without it.

We report theoretical and experimental work on the development of a vortex qubit based on a microshort in an annular Josephson junction. The microshort creates a potential barrier for the vortex, which produces a double-well potential under the application of an in-plane magnetic field; The field strength tunes the barrier height. A one-dimensional model for this system is presented, from which we calculate the vortex depinning current and attempt frequency as well as the interwell coupling. Implementation of an effective microshort is achieved via a section of insulating barrier that is locally wider in the junction plane. Using a junction with this geometry we demonstrate classical state preparation and readout. The vortex is prepared in a given potential well by sending a series of "shaker" bias current pulses through the junction. Readout is accomplished by measuring the vortex depinning current., Submitted to Physical Review B (13 pages, 10 figures). Changed content to include more explanation

We predict a new class of excitations propagating along a Josephson vortex in two-dimensional Josephson junctions. These excitations are associated with the distortion of a Josephson vortex line and have an analogy with shear waves in solid mechanics. Their shapes can have an arbitrary profile, which is retained when propagating. We derive a universal analytical expression for the energy of arbitrary shape excitations, investigate their influence on the dynamics of a vortex line, and discuss conditions where such excitations can be created. Finally, we show that such excitations play the role of a clock for a relativistically-moving Josephson vortex and suggest an experiment to measure a time dilation effect analogous to that in special relativity., Comment: 10 pages, 2 figures

We predict surface electromagnetic waves propagating across the layers of intrinsic Josephson junctions. We find the spectrum of the surface waves and study the distribution of the electromagnetic field inside and outside the superconductor. The profile of the amplitude oscillations of the electric field component of such waves is peculiar: initially, it increases toward the center of the superconductor and, after reaching a crossover point, decreases exponentially., Comment: 11 pages, 5 figures

We develop a perturbation theory that describes bound states of solitons localized in a confined area. External forces and the influence of inhomogeneities are taken into account as perturbations to exact solutions of the sine-Gordon equation. We have investigated two special cases: a fluxon trapped by a microresistor and decay of a breather under dissipation. We have also carried out numerical simulations with the dissipative sine-Gordon equation and made a comparison with the McLaughlin-Scott theory. A significant distinction between the McLaughlin-Scott calculation for a breather decay and our numerical result indicates that the history dependence of the breather evolution cannot be neglected even for a small damping parameter.

We describe a novel effect related to the controlled birth of a single Josephson vortex. In this phenomenon, the vortex is created in a Josephson transmission line at a T-shaped junction. The "baby" vortex arises at the moment when a "mother" vortex propagating in the adjacent transmission line passes the T-shaped junction. In order to give birth to a new vortex, the mother vortex must have enough kinetic energy. Its motion can also be supported by an externally applied driving current. We determine the critical velocity and the critical driving current for the creation of the baby vortices and briefly discuss the potential applications of the found effect.

We propose using the Josephson vortices (fluxons) as adjustable and malleable waveguides of electromagnetic radiation. Our theoretical and numerical calculations show that electromagnetic waves can propagate along the Josephson vortices and always follow the vortex lines. By changing external parameters, such as electric currents or magnetic fields, the shape and configuration of the guiding vortex lines can be controlled. We describe the design of a multifunctional three-terminal device that controls the transmission (redirecting or splitting) of a beam of electromagnetic waves.

We describe a device for generation and trapping of fluxon?antifluxon (FA) pairs in a long annular Josephson junction. The trapped fluxons and antifluxons experience multiple collisions and eventually decay into plasmons. We analyse the energy dissipation in the system and find the criteria for trapping of the FA pair. We describe a possible experiment for realization of multiple FA trapping and formation of a FA plasma. Similar to vortex liquids discussed recently by Anderson it might be a good candidate for another vortex liquid. The proposed device can be made of niobium or high temperature superconductors.