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61.
The features of the magnon spectrum in easy-plane multiferroics (such as BiFeO3), which allow inhomogeneous magnetoelectric (flexomagnetoelectric) interaction P[(L?)L ? LdivL], where L and P are the antiferromagnetic moment and electric polarization, respectively, have been theoretically analyzed. It has been shown that, in contrast to the magnon spectrum of a usual easy-plane antiferromagnet, a multiferroic with this magnetic structure is characterized by, first, the interaction between magnons of both branches propagating along the weak ferromagnetic moment and the appearance of a minimum (or zero) of the frequency of one of the branches, which reflects the instability of the system with respect to the transition to an inhomogeneous state with increasing flexomagnetoelectric interaction and, second, the nonequivalence (nonreciprocity) of the propagation of spin waves along and against the antiferromagnetism vector, which coincides with the toroidal moment in this system. 相似文献
62.
In this paper we establish conditions under which a topology is continued from a subset of a group to a topology on the group coordinated with the group operation. 相似文献
63.
V.Yu. Ivanov A.A. Mukhin V.D. Travkin A.S. Prokhorov A.M. Kadomtseva Yu.F. Popov G.P. Vorob’ev K.I. Kamilov A.M. Balbashov 《Journal of magnetism and magnetic materials》2006
Multiferroic ground states with a spatially modulated antiferromagnetic structure and electric polarization have been revealed in Eu1−xYxMnO3 (0.2?x?0.5) single crystals. While the slightly substituted (x?0.1) compounds exhibited a transition from the incommensurate (IC) to the canted antiferromagnetic (CAF) state at TCA<TN, the transitions from IC to commensurate ferroelectric (C/FE) phase were observed at Tlock<TN for x>0.2. Various phase transitions were observed in the magnetic fields up to 250 kOe along a, b, c axes by magnetization, magnetostriction and electric polarization measurements which show an existence of a spontaneous electric polarization below Tlock. 相似文献
64.
65.
A. E. Gorodetskyi R. Kh. Zalavutdinov V. L. Bukhovets I. I. Arkhipov A. P. Zakharov E. E. Mukhin A. G. Razdobarin S. Yu. Tolstyakov A. A. Sitnikova D. A. Kirilenko S. V. Masyukevich 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2012,6(5):865-872
Multilayered prototypes of Al and Ag total reflection mirrors with a protective coating of amorphous ZrO2 oxide were analyzed using transmission electron (cross-sectional method), optical, and scanning (with electron probe microanalysis) microscopes. The prototypes’ reflectivity was measured by the recording of reflection spectra in the wavelength range 200–1100 nm. The structure of the mirrors was studied by X-ray diffraction reflection. High temperature annealing (8 h) did not change the stoichiometric composition of the protective coating. The reflectivity of the Al mirrors in the wavelength range 700–1100 nm and the Ag mirrors in the wavelength range of 500–1100 nm remained unchanged in spite of recrystallization of the polycrystalline metal films and the incipient process of amorphous ZrO2 crystallization. The mass of the crystalline oxide after annealing was several percent of the total amorphous oxide mass. At the same time annealing led to the occurrence of local voids on the aluminum/upper oxide interface. Such defects were not observed on the Ag mirrors. As a whole, the Ag mirrors turned out to be more stable to heating as compared to those made of Al. 相似文献
66.
We consider a version of the A
N
Bethe equation of XXX type and introduce a reporduction procedure constructing new solutions of this equation from a given one. The set of all
solutions obtained from a given one is called a population. We show that a population is isomorphic to the sl
N
+1 flag variety and that the populations are in one-to-one correspondence with intersection points of suitable Schubert cycles
in a Grassmanian variety. We also obtain similar results for the root systems B
N
and C
N
. Populations of B
N
and C
N
type are isomorphic to the flag varieties of C
N
and B
N
types respectively. 相似文献
67.
S. V. Golovkin A. P. Kozhevnikov V. P. Kubarovsky A. I. Kulyavtsev V. F. Kurshetsov L. G. Landsberg V. V. Molchanov V. A. Mukhin I. N. Nikitin V. I. Solyanik D. V. Vavilov V. A. Victorov M. Ya. Balatz G. V. Dzubenko G. S. Lomkatsi V. T. Smolyankin 《Zeitschrift für Physik A Hadrons and Nuclei》1997,359(4):435-444
In the experiments with LEPTON-F and SPHINX spectrometers the pion-induced charged exchange reactions π- + p → ? + n and π- + p → ω + n at Pπ-=32.5 GeV, as well as proton-induced diffractive reactions p + N → [p?] + N and p + N → [pω] + N at E p =70 GeV were studied. The comparison of the cross-sections for ? and ω-production in these reactions is used for testing the OZI selection rule in hadronic processes. It has been demonstrated that in pion reactions the ratio of the yields of ? and ω-mesons R(?/ω) = (3 ± 1) · 10?3 is in a good agreement with naive quark model prediction based on the mixing in vector meson nonet and on the OZI rule (R(?/ω)ozi = tg 2Δθ V ? 4 · 10?3). At the same time in proton reactions the effective ratio of ? and ω yields is ~ (4 ÷ 7) · 10-2, i.e. a strong violation of the OZI rule is observed in proton-nucleon interactions. This violation can be in favor of possible existence of some exotic ss? component in the quark structure of protons. 相似文献
68.
An ideal antiferromagnetic (AF) ordering of the spins of the CuO layers of an underdoped cuprate prevents the low energy tunneling of the charge carriers between the layers. In order to obtain a non-vanishing c-axis conductivity (σc), we invoke ground state fluctuations of the spin system. These provide a frequency-dependent gating effect by changing the direction of the AF order parameter within one layer relative to that in a neighboring layer, thereby permitting some tunneling. The calculated σc compares favorably with experimental data in a) being small and b) having a weak frequency dependence of distinctly non-Drude form. 相似文献
69.
Gibbons L Johnson SD Kwon Y Roberts S Thorndike EH Jessop CP Lingel K Marsiske H Perl ML Schaffner SF Wang R Coan TE Dominick J Fadeyev V Korolkov I Lambrecht M Sanghera S Shelkov V Stroynowski R Volobouev I Wei G Artuso M Efimov A Gao M Goldberg M He D Horwitz N Kopp S Moneti GC Mountain R Mukhin Y Playfer S Skwarnicki T Stone S Xing X Bartelt J Csorna SE Jain V Marka S Freyberger A Gibaut D Kinoshita K Pomianowski P Schrenk S Cinabro D Barish B Chadha M Chan S Eigen G Miller JS O'Grady C 《Physical review letters》1996,77(5):810-813
70.
Crawford G Daubenmier CM Fulton R Fujino D Gan KK Honscheid K Kagan H Kass R Lee J Sung M White C Wolf A Zoeller MM Butler F Fu X Nemati B Ross WR Skubic P Wood M Bishai M Fast J Gerndt E Hinson JW McIlwain RL Miao T Miller DH Modesitt M Payne D Shibata EI Shipsey IP Wang PN Battle M Ernst J Gibbons L Kwon Y Roberts S Thorndike EH Wang CH Dominick J Lambrecht M Sanghera S Shelkov V Skwarnicki T Stroynowski R Volobouev I Wei G Zadorozhny P Artuso M Gao M Goldberg M He D Horwitz N Moneti GC 《Physical review letters》1995,75(4):624-628