摘要:

The effect of weak scalar potential on a persistent current in a one-dimensional ballistic ring is considered. It is shown that the current amplitude oscillates with a change in the potential. ©1997 American Institute of Physics.

ISSN:1063-777X    

DOI:10.1063/1.593401

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

Tunneling of electrons through a double-barrier system is considered in the approximation of low-transparency barriers taking into account the Coulomb interaction of electrons in the interbarrier space (quantum well). The state of the electrons in the quantum well is supposed to be doubly degenerate. It is shown that the dependence of the tunneling current on the applied voltage has a step-like form at low temperatures and has a threshold in the low-voltage region. The system under consideration also exhibits bistability. ©1997 American Institute of Physics.

ISSN:1063-777X    

DOI:10.1063/1.593402

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

An anyon exciton formed by a valence hole and three quasielectrons of the Laughlin incompressible liquid of the fractional quantum Hall effect with the filling factor&ngr;=1/3is investigated numerically in a spherical geometry. The quasielectrons ar treated as Bose particles with hard cores and the Coulomb interaction. The energy spectrum of the system and the quasielectron density distribution around the hole are obtained. The energy spectrum of the system has branches which can be classified according to intrinsic angular momentum of an anyon exciton; the absence of branches with an angular momentum below three and a branch with an angular momentum equal to four is a consequence of the Pauli exclusion principle for quasielectrons. ©1997 American Institute of Physics.

ISSN:1063-777X    

DOI:10.1063/1.593403

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

The relation between the temperature and the intensity distribution in luminescence bands in VUV and VIS spectral regions of Ne crystals is investigated. The measurements are made by using cathodoluminescent spectroscopy with steady-state excitation and are supplemented by observations of luminescence decay in perfect pure crystals, in samples with defects, and in solid solutions with electronegative (oxygen) and electropositive (xenon) impurities. The contribution of the recombination channel to the formation of the spectrum of self-trapped states in solid neon is determined. It is shown that this channel plays a decisive role in the population of3p(3p)luminescence centers and makes a relatively small contribution to the population of the lowermost3s(3s)excitations. The recombination channel efficiency strongly depends on temperature, increasing abruptly with the temperature value. An analysis of experimental data leads to the conclusion on the possibility of electron self-trapping in Ne cryocrystals, followed by the formation of shallow self-trapped states. ©1997 American Institute of Physics.

ISSN:1063-777X    

DOI:10.1063/1.593404

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

Samples of strongly dilute solid solutions of Ne inn-H2are tested under step-wise axial extension at temperatures1.8–4.2 K.A clearly manifested plasticization effect of neon impurities has been observed: smaller loads are required for crystals with a higher neon concentration to obtain the same strain at a fixed temperature. The ultimate strength of neon-doped crystals is noticeably lower than for pure samples of normal hydrogen. The creep of such solid solutions has also been studied. The decrease in the strength ofn-H2can be due to a specific mechanism of overcoming by dislocations of the barrier formed near impurities which probably form Van der Waals complexes with the crystal environment. ©1997 American Institute of Physics.

ISSN:1063-777X    

DOI:10.1063/1.593405

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

The low-temperature heat capacity of cuprates(La2CuO4,La2−xMxCuO4(M = Sr, Ba)andNd2−xLaxCuO4)is studied in the temperature range 2–45 Kby using pulsed differential calorimetry. It is found that the coefficient of the linear term of heat capacity remains unchanged over the entire temperature interval under investigation. The special role of La atoms in the formation of the anomaly in the acoustic region of the phonon spectrum of these compounds near6 meVis demonstrated. This anomaly is connected with peculiarities in the interaction of these atoms with the environment. ©1997 American Institute of Physics.

ISSN:1063-777X    

DOI:10.1063/1.593406

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

It is noted that the existing theory of magnetocapacity of screened2Delectron systems becomes meaningless in the vicinity of magnetocapacity minima. A modification of this theory eliminating these limitations is proposed. The derived equations are used for calculating the lowest magnetovcapacity of a parallel-plate capacitor in which one plate is a2Delectron system. ©1997 American Institute of Physics.

ISSN:1063-777X    

DOI:10.1063/1.593407

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

A comparison of field dependences of the meridional Kerr effect and magnetization leads to the conclusion that a noncollinear inhomogeneous magnetic state is formed in the surface layer of gadolinium in multilayered Gd/Fe films in a magnetic field. Experimental results are described by using a theoretical model predicting the formation of a noncollinear spin configuration in the surface Gd layer as a result of a spin-reorientation phase transition induced by the magnetic field. ©1997 American Institute of Physics.

ISSN:1063-777X    

DOI:10.1063/1.593408

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

The effect of VUV undulator excitation intensity on the emission shape and decay time ofBaF2crystal at low temperature has been observed. The findings are explained in terms of quenching of Auger-free luminescence (cross luminescence) by self-trapped exciton via Fo¨rster mechanism energy transfer. ©1997 American Institute of Physics.

ISSN:1063-777X    

DOI:10.1063/1.593409

出版商:AIP    

年代:1997

数据来源: AIP

摘要:

The possibility of coexistence of free and self-trapped excitons in one-dimensional molecular chains(J-aggregates) has been proved on the basis of experimental study of time-resolved low-temperature luminescence spectra. ©1997 American Institute of Physics.

ISSN:1063-777X    

DOI:10.1063/1.593480

出版商:AIP    

年代:1997

数据来源: AIP