Time evolution of spin state of radical ion pair in microwave field: An analytical solution

The paper reports an exact solution for the problem of spin evolution of radical ion pair in static magnetic and resonant microwave field taking into account Zeeman and hyperfine interactions and spin relaxation. The values of parameters that provide one of the four possible types of solution are analysed. It is demonstrated that in the absence of spin relaxation, besides the zero field invariant an invariant at large amplitudes of the resonant microwave field can be found. The two invariants open the possibility for simple calculation of microwave pulses to control quantum state of the radical pair. The effect of relaxation on the invariants is analysed and it is shown that changes in the high field invariant are induced by phase relaxation.Comment: 18 pages, 7 figure

Fractal formation and ordering in random sequential adsorption

We reveal the fractal nature of patterns arising in random sequential adsorption of particles with continuum power-law size distribution, $P(R)\sim R^{\alpha-1}$, $R \le R_{\rm max}$. We find that the patterns become more and more ordered as $\alpha$ increases, and that the Apollonian packing is obtained at $\alpha \to \infty$ limit. We introduce the entropy production rate as a quantitative criteria of regularity and observe a transition from an irregular regime of the pattern formation to a regular one. We develop a scaling theory that relates kinetic and structural properties of the system.Comment: 4 pages, RevTex, 4 postscript figures. To appear in Phys.Rev.Let

Effect of High Energy Ion Implantation on the Structure and Mechanical Properties of Aluminium Alloys

The effect of implantation of Ne⁺, Kr⁺, and Bi⁺ ions over the energy range 26-710 MeV on the structural-phase state and the mechanical properties of the aluminum-based alloys (Al-Cu, Al-Cu-Mg, Al-Cu-Zn, Al-Mn) was studied. The revealed peculiarities of variations in the structure, phase composition, and mechanical properties of aluminum alloys are attributed to the electron deceleration of ions making the principal contribution to the formation of radiation defects which enhance the diffusion processes in the targets

The formation of low-dimensional structures by compressive plasma flows

The process of the deposition of low-dimensional structures on the silicon surface exposed to the compression plasma flow has been studied. Scanning electron microscopy, transmission electron microscopy and Rutherford backscattering spectroscopy have been used to analyze the morphology, microstructure and elemental composition of the near-surface layer. The deposited coating consists of a spherical metal containing particles with a size of 50–200 nm. Possible mechanism of the coating formation is discussed

Iron surface cellular structure formed by action of compression plasma flows

Polygonal cellular structure on the surface of iron samples appear as a result of processing by compression plasma flows. Typical cell size of this structures is about 400 nm. Formation of such structure takes place during the melt crystallization when the melt is concentrated and undercooled

Iron surface cellular structure formed by action of compression plasma flows

Polygonal cellular structure on the surface of iron samples appear as a result of processing by compression plasma flows. Typical cell size of this structures is about 400 nm. Formation of such structure takes place during the melt crystallization when the melt is concentrated and undercooled