•Correlation of Sn-content in BaM hexaferrites, phase composition and MW properties was observed.•Impact of heterovalent substitution on Ms and Hc was discussed.•High electromagnetic absorption was ...achieved in 2–4 GHz frequency range.•More than 99.9% of the incoming electromagnetic radiation was absorbed.
Hexaferrites are usually used in devices for frequencies of 8–75 GHz. In this work, it is shown that Sn-substituted hexaferrite can be used for electromagnetic shielding and at lower frequencies (for example, in the L-band and S-band) as absorbing materials. The paper defines a solid-state reaction technique for preparing BaFe12−xSnxO19 (0.1 ≤x ≤ 1.2). The samples are characterized by XRD, SEM, VSM, and VNA. The study shows that increasing the Sn-substitution leads to weakening the interaction between the magnetic sublattices. So, in general, the saturation magnetization (Ms) decreases. Low saturation magnetization at high coercivity values
gives a high anisotropy field, which provides significant absorption and matching impedance. The sample with substitution of x = 1.2 is the most absorbing sample (more than 99.99% of the incident energy absorbed for 10 mm thickness). The investigated samples have the potential to be useful absorption materials for shielding production (materials that absorb electromagnetic radiation)
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
For solid-state spin qubits, single-gate rf readout can minimize the number of gates required for scale-up since the readout sensor can integrate into the existing gates used to manipulate the ...qubits. However, state-of-the-art topological error correction codes benefit from the ability to resolve the qubit state within a single shot, that is, without repeated measurements. Here, we demonstrate single-gate, single-shot readout of a singlet-triplet spin state in silicon, with an average readout fidelity of 82.9% at 3.3 kHz measurement bandwidth. We use this technique to measure a tripletT−to singletS0relaxation time of 0.62 ms in precision donor quantum dots in silicon. We also show that the use of rf readout does not impact the spin lifetimes (S0toT−decay remained approximately 2 ms at zero detuning). This establishes single-gate sensing as a viable readout method for spin qubits.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UL, UM, UPUK
Abstract
A complex (dusty) plasma system is well known as a paradigmatic model for studying the kinetics of solid-liquid phase transitions in inactive condensed matter. At the same time, under ...certain conditions a complex plasma system can also display characteristics of an active medium with the micron-sized particles converting energy of the ambient environment into motility and thereby becoming active. We present a detailed analysis of the experimental complex plasmas system that shows evidence of a non-equilibrium stationary coexistence between a cold crystalline and a hot fluid state in the structure due to the conversion of plasma energy into the motion energy of microparticles in the central region of the system. The plasma mediated non-reciprocal interaction between the dust particles is the underlying mechanism for the enormous heating of the central subsystem, and it acts as a micro-scale energy source that keeps the central subsystem in the molten state. Accurate multiscale simulations of the system based on combined molecular dynamics and particle-in-cell approaches show that strong structural nonuniformity of the system under the action of electostatic trap makes development of instabilities a local process. We present both experimental tests conducted with a complex plasmas system in a DC glow discharge plasma and a detailed theoretical analysis.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
A review of experimental studies of the properties of a recently discovered new coherent collective state, a magnetoexciton condensate, is presented. Condensation occurs at temperatures below 1 K in ...a Fermi system, a quantum Hall insulator (a filling factor of ν = 2), as a result of the formation of a dense ensemble of long-lived triplet spin cyclotron magnetoexcitons—composite bosons. The condensed phase interacts coherently with an external electromagnetic field and demonstrates the ability of fast nondiffusive propagation over macroscopic distances and high spatial coherence.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The dynamical properties are studied of a system of a finite number of likely charged particles that interact via a screened Coulomb potential in the field of a parabolic trap. By the normal mode ...analysis, the spatial distribution of oscillation amplitudes of particles in the system is obtained in the quasiharmonic approximation: high-frequency oscillations are localized in the central region of the system. This leads to the fact that the vibrational spectra of particles are different in different regions of the structure. To generalize this result to a wide temperature range, a numerical analysis of systems of a finite number of particles in a trap is carried out by the classical molecular dynamics method. It is shown that the spectra of thermal vibrations of particles are spatially inhomogeneous: a spectrum is shifted to the low-frequency region as the distance from the subsystem under consideration to the center of the structure increases. Various methods for calculating the amplitude of thermal vibrations of particles, both within the quasiharmonic approximation and by the molecular dynamics method, confirm the inhomogeneity of the radial amplitude profile: the amplitude of thermal vibrations of particles at the periphery of the system is higher than that at the center of the structure. It is shown that, in the local approximation, the dynamical properties of subsystems of structures consisting of a finite number of charged particles in a trap under certain conditions are significantly different from the dynamical properties of systems of charged particles of similar density under periodic boundary conditions (PBCs). The results of this study may be useful in describing the dynamical properties of laboratory dusty plasma and colloidal systems.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Coherent condensate states of particles obeying either Bose or Fermi statistics are in the focus of interest in modern physics. Here we report on condensation of collective excitations with Bose ...statistics, cyclotron magnetoexcitons, in a high-mobility two-dimensional electron system in a magnetic field. At low temperatures, the dense non-equilibrium ensemble of long-lived triplet magnetoexcitons exhibits both a drastic reduction in the viscosity and a steep enhancement in the response to the external electromagnetic field. The observed effects are related to formation of a super-absorbing state interacting coherently with the electromagnetic field. Simultaneously, the electrons below the Fermi level form a super-emitting state. The effects are explicable from the viewpoint of a coherent condensate phase in a non-equilibrium system of two-dimensional fermions with a fully quantized energy spectrum. The condensation occurs in the space of vectors of magnetic translations, a property providing a completely new landscape for future physical investigations.
The analysis is based on the relations characterizing charged particles’ motion in the drift approximation (D. V. Sivukhin, in
Reviews of Plasma Physics,
Ed. by M. A. Leontovich (Consultants Bureau, ...New York, 1965), Vol. 1, p. 1; B. A. Trubnikov,
Introduction to
Plasma Theory
(Mos. Inzh. Fiz. Inst., Moscow, 1968) in Russian). It is noted that the particles can be accelerated using the device proposed in the work (A. V. Timofeev, Sov. J. Plasma Phys.
4
, 464 (1978)) for the inverse process of converting the particles’ chaotic motion energy into electric energy. The magnetic field of such a system is similar to that of the rectilinear current-carrying conductor. In the work (A. D. Beklemishev, Phys. Plasmas
22
, 103506 (2015)), for particle acceleration, it was proposed to use the magnetic field, which is the superposition of the homogeneous field and the helical field with a varying period. In such a system, the charged particles’ acceleration can be considered to be the result of the Cherenkov resonance interaction of particles with the zero-frequency electric field. During the particles’ acceleration, the resonance conditions can be maintained due to the autophasing process, which is a consequence of the constancy of the corresponding adiabatic invariant (A. I. Neishtadt and A. V. Timofeev, Sov. Phys. JETP
66
, 973 (1987)). To ensure these conditions, the helical field period should vary quite slowly along the system’s axis.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Abstract
We study the spatial distribution of dynamical properties in a strongly coupled confined experimental dust monolayer with a dense central region and a rarefied periphery. We show that the ...dust particle oscillations spectrum shifts into the low-frequency range from the center of the structure toward its periphery. Correspondingly, the high-frequency particle oscillations are localized in the central region of the system. This effect is quantitatively described within the framework of the model system of trapped screened Coulomb charges. Such spatial localization has a significant effect on the spatial distribution of dynamical parameters, such as the amplitude of particle oscillations and the coupling parameter. The obtained results might be useful for the theory of crystal formation, instabilities and phase transitions in complex (dusty) plasmas, colloidal suspensions, and Coulomb crystals.
The dynamic properties of a quasi-two-dimensional dusty plasma structure consisting of negatively charged dust particles have been studied. The interaction between the particles is described taking ...into account the asymmetry of the distribution of the electrostatic potential around them. Asymmetry is caused by the presence of an ion flow in the region of existence of a monolayer and leads to the violation of reciprocity of the effective interactions between particles and the violation of Newton’s third law for them. It has been demonstrated that the spatial distribution of the dynamic properties of the dusty plasma monolayer such as the kinetic energy of the particles, the amplitude of their thermal vibrations, and the nonideality parameter in the system are generally nonuniform. The central region of the ordered monolayer can be both more and less nonideal than the boundary region, depending on the parameters of the dusty plasma. This unique effect occurs because a hybrid mode can appear in the center of the monolayer without the melting of the system. The characters of inhomogeneity of the dynamic properties of the Yukawa and dusty plasma monolayers are significantly different. The results obtained allow a qualitatively new view on the dynamic properties of strongly nonideal dusty plasma systems.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
•Annealing of BaFe12O19/Al2O3 (102) films led to the formation of a layered structure.•Surface layer of BaFe12O19/Al2O3 (102) films could have (00l) crystal texture.•The morphology of the surface ...BaFe12O19/Al2O3 (102) depends on the substrate temperature.•The thickness of BaFe12O19 film influences the type of its texture after annealing.
Barium hexaferrite thin films were prepared by ion beam deposition on sapphire (102) single crystal substrates. The structural properties of the films were analyzed by means of X-ray diffraction, atomic force microscopy, magnetic force microscopy and scanning electron microscopy. The obtained results were interpreted as a presence of layered structure with different types of texture and its formation mechanism is proposed. The significant influence of BaFe12O19 thickness on its microstructure was observed. Films obtained under certain conditions are potentially fit for further growing of oriented hexaferrite with out-of-plane orientation of c-axis.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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