摘要:

We propose a microscopic theory for the Aharonov–Bohm oscillations, observed by Latyshev &etal; in the magnetotransport experiment inNbSe3with a charge density wave (CDW). The CDW slides across an array of columnar defects in a high magnetic field. For the charge carrying quanta of CDW these defects are elementary solenoids carrying a magnetic flux. The quantum CDW current acquires a component oscillating with the flux, with the periodhc/2e.Its magnitude is proportional to the concentration of columnar defects. The lower limit to the phase breaking length for these oscillations is set by the minimal Lee–Rice coherence length. ©1998 American Institute of Physics.

ISSN:1063-777X    

DOI:10.1063/1.593656

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

Electron diffraction studies of the structural characteristics ofAr–CO2solid solutions are carried out over the entire range of their mutual concentrations. The regions of low concentrations of both components are analyzed in detail and the relative excess volumes&Dgr;v/vare determined for theCO2impurity in solid Ar(&Dgr;v/v≃0.8), and for the Ar impurity in solidCO2(&Dgr;v/v≃0.28). The experimental results and relationships are compared with the results obtained from the semi-quantitative theory on the basis of known atom–atom potentials. An expression relating the intensity of superstructural reflectionsI(super)(including the reflection 210) with the long-range orientational order parameter&eegr;is obtained. It is found thatI210∝&eegr;2to a high degree of precision. The experimental dependence of the orientational order parameter&eegr;on the argon concentration in solutions rich inCO2is obtained. ©1998 American Institute of Physics.

ISSN:1063-777X    

DOI:10.1063/1.593662

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

Low-temperature field reconstruction of atomic clusters at a closely packed face of a metal is observed for the first time by the method of field ion microscopy. It is found that compact clusters disintegrate into non-closely packed zigzag atomic chains. ©1998 American Institute of Physics.

ISSN:1063-777X    

DOI:10.1063/1.593657

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

The frequency renormalization of acoustic phonons interacting with a double-layer composite fermion system is calculated. The space distribution of the density of the charge induced by an external electrostatic potential in a double-layer composite fermion system is determined. It is shown that for a filling factor for which states with the interlayer statistical interaction and without it can be realized, the emergence of such an interaction causes a jump in the phase velocity of a finite-frequency acoustic phonon and changes the space distribution of the charge induced by the external potential. These effects can be used for observing a transition in a double-layer electron system under the conditions of the fractional quantum Hall effect to a new ground state upon a decrease in the separation between the layers. ©1998 American Institute of Physics.

ISSN:1063-777X    

DOI:10.1063/1.593658

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

The microscopic theory of the dc Josephson effect for a short clean superconducting point contact with a tunnel barrier is developed. The influence of the ordinary quasiparticle scattering on the nondiagonal potential &Dgr; of the superconductor is studied. It is shown that such processes may be significant in high-Tcsuperconductors for the case of a barrier with high transmittance. The current-phase relation for a point contact at arbitrary temperatures is calculated. ©1998 American Institute of Physics.

ISSN:1063-777X    

DOI:10.1063/1.593659

出版商:AIP    

年代:1998

数据来源: AIP

摘要:

Investigations of magnetic and spontaneous birefringence properties of aKDy(MoO4)2crystal under the Jahn–Teller phase transformation reveal some features indicating the existence of two spontaneous phase transitions at temperatures close to 14.3 and11.0&hthinsp;K. The characteristic changes in birefringence in these transitions suggest that the crystal of KDy molybdate has a modulated incommensurate lattice structure in the temperature range from 11.0 to14.3&hthinsp;K. ©1998 American Institute of Physics.

ISSN:1063-777X    

DOI:10.1063/1.593660

出版商:AIP    

年代:1998

数据来源: AIP