Magnetoplasmon modes in the response of a mesoscopic particle of a semimetal or a nonmagnetic insulator

The macroscopic features of the behavior of a mesoscopic particle in a magnetic field are investigated for mesoscopic particles possessing the properties of a semimetal or a nonmagnetic insulator. It is shown that for a fixed value of the magnetic field the frequency of the Alfve’n magnetoplasma mode falls off monotonically (as 1/R) as the radius of the particle increases. Pis’ma Zh. Tekh. Fiz. 23, 16–21 (December 12, 1997)     

Dispersion of a charged bubble in a liquid dielectric in a electrostatic field

It is predicted that the size and charge of daughter bubbles emitted in an electrostatic field from different tips of a charged parent bubble will differ. Pis’ma Zh. Tekh. Fiz. 24, 30–35 (December 26, 1998)     

Undamped self-oscillations in a compensated semiconductor under conditions of impurity breakdown in the presence of a magnetic field

Conditions for the generation of undamped self-oscillations in a compensated semiconductor in the presence of a magnetic field are studied. Pis’ma Zh. Tekh. Fiz. 23, 62–66 (August 26, 1997)     

Stressed state of a matrix and an inclusion made from a twisted composite superconductor in cladding when a circular current interacts with a magnetic field

This paper discusses the stressed state of the matrix and a long wire made from a twisted multicore composite superconductor and encased in cladding when the circular component of the transport current interacts with a magnetic field. Pis’ma Zh. Tekh. Fiz. 24, 1–6 (January 26, 1998)     

Anisotropic scattering of polarized light in a ferrofluid layer

Previously unknown effects wherein the scattering of plane-polarized light in a ferrofluid layer depends on the orientation of the electric field of the polarized radiation relative to the direction of the applied magnetic field are found experimentally, and their physical nature is explained. Pis’ma Zh. Tekh. Fiz. 23, 7–10 (September 12, 1997)     

Stress field at the boundary of a wedge-shaped twin

A model is proposed to calculate the stress field at the boundary of a wedge-shaped twin which can allow for its degree of coherence. It is shown that the stress field decreases exponentially with increasing distance from the twinning boundary. Pis’ma Zh. Tekh. Fiz. 23, 1–6 (November 26, 1997)     

Formation of a honeycomb domain structure in magnetic films

An analysis is made of the possible formation of a honeycomb domain structure directly from a labyrinth structure in uniaxial magnetic films exposed to a series of uniform magnetic field pulses. It is shown that the scenario for the formation of a honeycomb structure depends on the pulse parameters and on the magnitude of the static magnetizing magnetic field. Pis’ma Zh. Tekh. Fiz. 23, 46–51 (May 12, 1997)     

Spin-orbit interaction in the field of an optical vortex of a few-mode fiber

A quantum-mechanical analog of the spin-orbit interaction operator is constructed for the fields of optical CV vortices and TE and TM modes in an optical fiber. It is shown that the polarization correction δβ to the propagation constant, which is the mean value of this operator, is a measure of the “level splitting” of the propagation constant in the scalar case. The difference in the operation of the individual parts of the operator on the fields of CV vortices and on the fields of TM and TE modes is indicative of the presence of two different physical processes — circular and linear birefringence in the locally isotropic optical fiber. The conversion of the “scalar” field to a vector field e ₁ as a consequence of the spin-orbit interaction operator can be regarded as resulting from a re-radiation of the additional field e ₁ by the vortex field , which rotates around the optical axis of the fiber. In this picture the additional field e ₁ can be regarded as being a “relativistic” correction to the vortex field for the distortions of the main field and arising as a result of the rotation of the field of the optical vortex in the medium of the few-mode fiber. Zh. Tekh. Fiz. 24, 87–93 (October 26, 1998)     

Possible emission of supermodes in a free electron laser with a transversely developed interaction space

A theoretical analysis is made of the formation of the transverse field profile in a free electron laser with an oversize planar-geometry Bragg cavity driven by a ribbon electron beam. It is shown that cw spatially coherent lasing may be achieved with an oversize parameter of the order of 50 with the excitation of supermodes comprising a set of “ cold” waveguide modes. Pis’ma Zh. Tekh. Fiz. 25, 28–34 (March 12, 1999)     

Induced of zeeman coherence in an ensemble of cesium atoms interacting with a two-frequency (microwave+rf) magnetic field

Interference between Zeeman states corresponding to the forbidden magnetic-dipole transition ΔF=0, Δm _F=2 is reported in connection with the simultaneous interaction of 6² S _1/2 cesium atoms with a resonant microwave field and an rf field which varies at twice the Larmor frequency and is directed perpendicular to a static magnetic field H ₀=0.2 Oe. Pis’ma Zh. Tekh. Fiz. 24, 89–93 (July 26, 1998)     

Probing of a random phase screen by a focused spatially modulated laser beam. Diffraction at a large number of inhomogeneities

The contrast of the Young’s interference fringes formed in the diffraction field when a dynamic random phase screen is illuminated by a focused, spatially modulated laser beam is obtained analytically as a function of the statistical parameters of the screen. A threshold relative bleaching effect is established for a highly dispersive medium when a low-divergence illuminating beam is used. Pis’ma Zh. Tekh. Fiz. 23, 47–53 (October 12, 1997)     

Magnetic-field control of gas flow in a supersonic intake

A numerical simulation is used to assess the potential for controlling the flow structure in the air intake of a supersonic aircraft by means of an external magnetic field. Pis’ma Zh. Tekh. Fiz. 23, 1–5 (August 26, 1997)     

Controllable electrochromic effect in a liquid-crystal cell with J aggregates

It is shown that organic nanocrystals (J aggregates) can be successfully produced and oriented in a liquid-crystal matrix. An external electric field can reorient and destroy them. Pis’ma Zh. Tekh. Fiz. 25, 6–10 (October 12, 1999)     

Oscillatory instability of the interface between conducting liquids in a normal electric field

It is shown that a new type of oscillatory instability, unlike the Tonks-Frenkel instability, may occur at a charged interface between two electrically conducting liquids in a perpendicular electrostatic field. Pis’ma Zh. Tekh. Fiz. 23, 41–44 (August 26, 1997)     

Anomalously high conductivity in a thin polyphthalidylidene biphenylene film

An anomalously high conductivity was observed for the first time in a thin film of polyphthalidylidene biphenylene inserted between two metal electrodes with no electric field applied but exposed to the action of a small uniaxial mechanical pressure. Pis’ma Zh. Tekh. Fiz. 24, 89–94 (July 12, 1998)     

Experiments on interferometric enhanced scattering in a plasma with a nonuniform magnetic field

Results are presented from the first experiments on interferometric enhanced scattering (IES) in a plasma in a nonuniform magnetic field. Measurements of the lower hybrid fluctuations of the plasma density by the IES and rf probe methods in an experimental geometry that models a tokamak configuration are found to be in satisfactory agreement. Pis’ma Zh. Tekh. Fiz. 24, 43–51 (October 26, 1998)     

Anisotropy of 63Ni diffusion in single-crystal silicon iron in a static magnetic field

An investigation is made of the influence of a static magnetic field on the diffusion of ⁶³Ni in single-crystal silicon iron. It is established that the diffusion coefficient depends on the annealing temperature, the external magnetic field strength, the direction of the Ni concentration gradient, and the crystallographic orientation of the sample, but does not depend on the direction of the field. Pis’ma Zh. Tekh. Fiz. 23, 33–38 (March 12, 1997)     

Trajectories of return surface magnetostatic waves in a ferrite-dielectric-metal structure magnetized by a nonuniform “ridge” field

Calculations are made of the trajectories of return surface magnetostatic waves (SMSWs) in a ferrite-dielectric-metal structure magnetized by a nonuniform “ridge” field. It is shown that there are four different types of trajectories. Conditions are determined for which the return SMSWs propagate in the direction opposite to the forward SMSWs and in the same direction as the forward SMSWs. Pis’ma Zh. Tekh. Fiz. 25, 61–66 (December 12, 1999)     

Surface light waves on the boundary of a photorefractive crystal with a diffusion-drift nonlinearity mechanism

All the possible types of surface light wave that can exist on the boundary of a photorefractive uniaxial crystal with a diffusion-drift nonlinearity mechanism are identified. It is shown that by varying the magnitude and direction of an external electric field E₀ one can control both the parameters and the type of the surface wave. In the particular case of zero field E₀ (the diffusion nonlinearity mechanism) the general solution agrees with the solution obtained in Ref. 5. Pis’ma Zh. Tekh. Fiz. 23, 31–36 (June 26, 1997)     

Influence of gas compressibility on the critical conditions for instability in the electrostatic field of a bubble in a dielectric liquid

It is shown that unlike the case of a liquid droplet, the critical strength of a uniform electrostatic field required for instability of a gas bubble in a liquid dielectric decreases as the compressibility of the gas in the bubble increases. Pis’ma Zh. Tekh. Fiz. 24, 49–54 (November 12, 1998)