Showing papers in "Jetp Letters in 1984"

Size quantization of the electron energy spectrum in a microscopic semiconductor crystal

Abstract: The interband absorption spectrum of microscopic CdS crystals ranging in size from ∼ 30 to 800 A and dispersed in a transparent insulating matrix has been studied. There is a significant (∼0.8-eV) shift of the fundamental absorption edge in the short-wavelength direction, and there are oscillations in the interband absorption spectrum caused by quantum size effect.

Generation of isothermal density perturbations in an inflationary universe

Abstract: Isothermal density perturbations with an amplitude sufficient for the subsequent formation of galaxies may be generated along with adiabatic density perturbations in an inflationary universe.

Long-lived induction signal in superfluid /sup 3/He-B

Abstract: The frequency of the ''long-lived'' induction signal in /sup 3/He-B depends on the time, and the rate of change of this frequency increases with increasing field gradient. Experiments confirm Fomin's theoretical explanation of this phenomenon, according to which a /sup 3/He-B sample in which a uniform magnetization precession is excited breaks up into two phases. In one, the magnetization is parallel to the field and does not precess; in the other, the magnetization precesses with a deflection angle of approximately 104/sup 0/.

Particle creation in a tunneling universe

Abstract: The problem of the behavior of quantized fields in the process of tunneling of a closed homogeneous isotropic universe is examined. It is shown that tunneling of the universe from the Friedman regime to the de Sitter regime is accompanied by catastrophic creation of particles.

Polarization shift of the levels of a muonic atom

Abstract: A polarization shift of the levels and a corresponding polarization potential has been found for muonic atoms with Zapprox.10--50, for which the Coulomb energy of the muon is on the order of or greater than the characteristic excitation energy of the nucleus.

Anisotropy of the upper critical field in exotic superconductors

Abstract: While the superconducting order parameter is characterized by a multidimensional representation of the rotation group (a state of the type /sup 3/He-A), the upper critical field near T/sub c/ is anisotropic even in a crystal with a high degree of symmetry. This circumstance can be used to describe the nature of the observed superconductivity. The degeneracy can in principle be lifted by elastic stress.

Renormalization of topological charge

Abstract: The contribution of instantons to the renormalization of the coefficient of the topological charge density in the effective Lagrangian is calculated. The relationship with the quantum Hall effect is discussed.

Layered structure of superfluid 4 He with supercritical motion

Abstract: It is shown that when superfluid /sup 4/He flows along a capillary with a velocity exceeding Landau's critical roton velocity, a one-dimensional periodic structure, which is at rest relative to the walls, appears in the helium and the spectrum of excitations is deformed so that the criterion of superfluidity is not violated.

Giant increase in the Curie temperature of RCo 2 intermetallic rare-earth compounds at low degrees of replacement of magnetic cobalt by nonmagnetic aluminum

Abstract: The intermetallic rare-earth compounds of the general formula R Cot (a C 15 Laves-phase cubic structure) are collinear ferrimagnets and have two magnetic subsystems. One is formed by the localized moments of the rare earth, while the other is formed by the moments of the collectivized 3d electrons of cobalt hybridized with 5d electrons of the rare earth. The exchange between the d electrons is insufficient for a spontaneous splitting of the d band, so that compounds with nonmagnetic rare earths 1igor, LuCo2) are exchange-intensified Pauli paramagnets'r and the magnetization of the d-electron subsystem in compounds with magnetic rare earths is due to an R-d exchange interaction, which is strongest in GdCot.

Phase-transition splitting caused in exotic superconductors by impurities

Abstract: The observed splitting of the superconducting transition in U/sub 1-x/Th/sub x/Be/sub 13/ is explained on the basis that with increasing temperature the thorium impurity initially disrupts the orientational long-range order characteristic of exotic superconductors )G. E. Volovik and L. P. Gor'kov, Pis'ma Zh. Eksp. Teor. Fiz. 39, 550 (1984) (JETP Lett. 39, 550 (1984))). The superconducting state is destroyed during a second transition.

Muon catalysis of dd nuclear fusion in the pressure range 51.6-93.0 atm

Abstract: The rate of production of dd..mu.. molecules at deuterium pressures of 51.6, 70.4, 79.6, 91.6, and 93.0 atm has been measured at a temperature of 293 K. The ratio of the yields of the dd fusion reactions and the effective muon attachment coefficient are determined.

Pinning of solitons by Abrikosov vortices in distributed Josephson junctions

Abstract: In a distributed Josephson junction the presence of an Abrikosov vortex in the superconducting film leads to a new type of perturbation of the sine-Gordon equation. This inhomogeneity makes it possible to distinguish the polarity of solitons and leads to several physical effects that can be observed experimentally.