铁磁金属的表面阻抗与自旋波共振

本文计算了铁磁金属在平行磁场中的表面阻抗。计算中考虑了交换作用所引起的磁化率空间色散及趋肤效应的反常性。分别讨论了磁矩的两种边界条件m=0和(?m)/(?n)=0。同时研究了导电电子在表面散射性质的影响。利用Азбель-Канер在迴旋共振理论中的方法,计算了考虑电导率旋磁性条件下的表面阻抗。     

Second order theory of excitations in trapped bose condensates at finite temperatures

We present a finite temperature field theory for collective excitations of trapped Bose condensates which includes the dynamics of the thermal cloud. In spherical traps we show that excitations couple strongly to a small number of modes, giving resonance structure in their frequency spectra. Where possible, we derive energy shifts and lifetimes of excitations. For the l = 0 mode we show that the simple picture of a decay rate fails, which should be observable in suitable experiments. It also suggests a possible explanation for the anomalous behavior of the m = 0 mode observed in anisotropic traps.     

On the scattering properties of a weakly charged polymer gel

A phenomenological model is presented to describe weakly charged polymer gels based on the classical elasticity theory. The structure factor of the gel is calculated considering both thermal and frozen concentration fluctuations as well as the screened Coulomb interaction. In agreement with the recent experimental finding the result shows anomalous crosslink-density dependence of the scattering profiles. Received: 28 March 1997 / Revised: 4 September 1997 / Accepted: 23 October 1997     

The Multifocus Structure of Radiation upon Femtosecond Filamentation of an Optical Vortex in a Medium with an Anomalous Group Velocity Dispersion

Optics and Spectroscopy - We analyze numerically the femtosecond filamentation of a vortex beam with the topological charge m = 1 at wavelength λ0 = 1800 nm in fused silica under anomalous...     

Molecular orbital theory for intermediate structure in the excitation function of heavy-ion reactions

In the excitation function for the elastic scattering between an α-conjugate target and projectile, there often exist intermediate structures which cannot be interpreted easily either by conventional optical potential model or statistical theory. A nuclear molecular-orbital approximation theory for the α-transfer mechanism has been formulated and applied to the ²⁴Mg(¹⁶O, ¹²C)²⁸Si reaction. The excitation function at θ_c.m. = 0° and differential cross section in the whole angle region at three different energies E_c.m.= 27.8, 30.8 and 36.2 MeV are calculated. The calculations reproduce well these experimental curves with a common set of parameters. The intermediate structures shown naturally in the excitation function and the anomalous oscillatory structures appear in the whole angle region of the differential cross section.     

Mixture-model approach to the theory of classical fluids. III. Application to aqueous solutions of nonelectrolytes

An extension of the mixture-model approach to the theory of liquid water is developed to include aqueous solutions of nonelectrolytes. The Kirkwood-Buff theory of solution is employed to obtain a general and exact expression for the stabilization effect induced by the solute. This relation is applied, in the framework of a two-structure model, to obtain further insight into the molecular origin of some anomalous thermodynamic properties of aqueous solutions. The generalized continuous mixture-model formalism is also extended to solutions. It is demonstrated that current concepts such as structural changes in the solvent are strongly dependent on the particular classification procedure adopted to construct the mixture model.     

Anomalous scaling at the quantum critical point in itinerant antiferromagnets

We show that the Hertz phi(4) theory of quantum criticality is incomplete as it misses anomalous nonlocal contributions to the interaction vertices. For antiferromagnetic quantum transitions, we found that the theory is renormalizable only if the dynamical exponent z=2. The upper critical dimension is still d=4 - z=2; however, the number of marginal vertices at d=2 is infinite. As a result, the theory has a finite anomalous exponent already at the upper critical dimension. We show that for d<2 the Gaussian fixed point splits into two non-Gaussian fixed points. For both fixed points, the dynamical exponent remains z=2.     

Anomalous heat conduction and anomalous diffusion in nonlinear lattices, single walled nanotubes, and billiard gas channels

We study anomalous heat conduction and anomalous diffusion in low-dimensional systems ranging from nonlinear lattices, single walled carbon nanotubes, to billiard gas channels. We find that in all discussed systems, the anomalous heat conductivity can be connected with the anomalous diffusion, namely, if energy diffusion is sigma(2)(t)=2Dt(alpha) (01) implies an anomalous heat conduction with a divergent thermal conductivity (beta>0), and more interestingly, a subdiffusion (alpha<1) implies an anomalous heat conduction with a convergent thermal conductivity (beta<0), consequently, the system is a thermal insulator in the thermodynamic limit. Existing numerical data support our theoretical prediction.     

Linear magnetization dependence of the intrinsic anomalous Hall effect

The anomalous Hall effect is investigated experimentally and theoretically for ferromagnetic thin films of Mn5Ge3. We have separated the intrinsic and extrinsic contributions to the experimental anomalous Hall effect and calculated the intrinsic anomalous Hall conductivity from the Berry curvature of the Bloch states using first-principles methods. The intrinsic anomalous Hall conductivity depends linearly on the magnetization, which can be understood from the long-wavelength fluctuations of the spin orientation at finite temperatures. The quantitative agreement between theory and experiment is remarkably good, not only near 0 K but also at finite temperatures, up to about approximately 240 K (0.8TC).     

Spin disorder scattering in magnetic metallic alloys

Anomalous behavior of the resistivity at or just below the Néel temperature in antiferromagnetic metals is usually attributed to the formation of superzone gaps. However, we find that RMn12-xFex alloys which have no such gaps exhibit a similarly anomalous resistivity. We show that electron scattering by substitutional spin disorder can account for such behavior of itinerant magnets. This mechanism, which has not been studied before, leads to a relaxation rate that is proportional to x(12-x)m(2), where m is the staggered magnetization. Together with spin fluctuations, phonon, and impurity scattering, it accounts well for the resistivity data we obtain for HoMn12-xFex, for 0< or =x< or =9, in the temperature range of 4 to 400 K.     

Contributions of weak and strong interactions to the anomalous magnetic moment of the electron

Based on Weinberg - Salam weak interaction theory, we have determined the addition to the anomalous magnetic moment of the electron arising from interaction between the electron and quantum fluctuations of the vector field (the carrier of the weak interaction). We also estimate the contribution of the strong interaction to the anomalous magnetic moment of the electron due to polarization of the quark — gluon vacuum. The overall contribution of the weak and strong interactions to the anomalous magnetic moment proves to be equal to 1·10^–12, and the contribution of the weak interaction is 2.2 times greater than the contribution of the strong interaction.Kamskii Polytechnical Institute. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 13–19, November, 1993.     

Quadrupole collective modes in trapped finite-temperature Bose-Einstein condensates

Finite-temperature simulations are used to study quadrupole excitations of a trapped Bose-Einstein condensate. We focus specifically on the m = 0 mode, where a long-standing theoretical problem is to account for an anomalous variation of the mode frequency with temperature. We explain this behavior in terms of the excitation of two separate modes, corresponding to the coupled motion of the condensate and the thermal cloud. The relative amplitude of the modes depends sensitively on the temperature and on the frequency of the harmonic drive used to excite them. Good agreement with experiment is found for appropriate drive frequencies.     

Correlated transport and non-Fermi-liquid behavior in single-wall carbon nanotubes

We derive the effective low-energy theory for single-wall carbon nanotubes including the Coulomb interactions among electrons. The generic model found here consists of two spin-fermion chains which are coupled by the interaction. We analyze the theory using bosonization, renormalization-group techniques, and Majorana refermionization. Several experimentally relevant consequences of the breakdown of Fermi liquid theory observed here are discussed in detail, e.g., magnetic instabilities, anomalous conductance laws, and impurity screening profiles. Received: 12 December 1997 / Revised: 9 March 1998 / Accepted: 12 March 1998     

On the interference absorption of X-rays in crystals with weak deformations

The problem of Borrmann absorption (anomalous absorption) of X-rays in weakly deformed crystals is considered on the basis of Takagi’s approach to the dynamical theory. Using wave function considerations, the attenuation of rays is represented by exp(−σl) where the attenuation factor σ includes a parameter of the lattice deformation field. The possibility of cases σ = 0 and even σ < 0 is discussed.     

The four-loop anomalous dimension of the Konishi operator in $$ \mathcal{N} $$ = 4 Supersymmetric Yang-Mills theory

We present the result of a full direct component calculation for the planar four-loop anomalous dimension of the Konishi operator in = 4 Supersymmetric Yang-Mills theory. Our result confirms the results obtained from superfield and superstring computations, which take into account finite size corrections to the all-loop asymptotic Bethe ansatz for the integrable models describing the spectrum of the anomalous dimensions of the gaugeinvariant operators and the spectrum of the string states in the framework of the gauge/string duality. The article is published in the original.     

Anomalous heat conduction and anomalous diffusion in one-dimensional systems

We establish a connection between anomalous heat conduction and anomalous diffusion in one-dimensional systems. It is shown that if the mean square of the displacement of the particle is =2Dt(alpha)(01) implies anomalous heat conduction with a divergent thermal conductivity (beta>0). More interestingly, subdiffusion (alpha<1) implies anomalous heat conduction with a convergent thermal conductivity (beta<0), and, consequently, the system is a thermal insulator in the thermodynamic limit. Existing numerical data support our results.     

Variations of soil radon and thoron concentrations in a fault zone and prospective earthquakes in SW Taiwan

An automatic station for soil gas monitoring was set up on an active fault zone of SW Taiwan. After more than one year of continuous measurements, some spike-like anomalous high radon and thoron concentrations could be observed. A similar soil radon spectrum was also obtained from an independent monitoring station, which was only 100 m away. These anomalous peaks usually occurred a few days or weeks before the earthquakes (M_L4.5). This indicates that variations of both soil radon and thoron can serve as useful tools for earthquake surveillance, esp. at fault zones.     

Some open questions in cholesteric blue phases

After a brief survey of the Landau theory of cholesteric blue phases (BP) several outstanding problems are presented. These include: (1) the nature of the anomalous fog phase, also known as BPIII(2) the question of forbidden lines in Bragg spectra and the structure of BPII, and (3) the non-cubic phases which become stable in the presence of an external field. The present status of these questions is reviewed and some directions for future work are indicated.Dedicated to Professor Harry Thomas on the occasion of his 60th birthday     

The calculation of the two-loop spin splitting functions $P_{ij}^{(1)}(x)$

We present the calculation of the two-loop spin splitting functions $P_{ij}^{(1)}(x)(i,j=q,g)$ contributing to the next-to-leading order corrected spin structure function g ₁ (x, Q²). These splitting functions, which are presented in the ${?erline {? MS}}$ scheme, are derived from the order $←pha_{s}^{2}$ contribution to the anomalous dimensions $αmma_{ij}^{m}(i,j=q,g)$. The latter correspond to the local operators which appear in the operator product expansion of two electromagnetic currents. Some of the properties of the anomalous dimensions will be discussed. In particular our findings are in agreement with the supersymmetric relation $αmma_{qq}^{m}+αmma_{gq}^{m}-αmma_{qg}^{m}-αmma_{gg}^{m}=0$ up to order $←pha_{s}^{2}$.     

Is It Possible to Study the Wave Function of 2S Vector Mesons at HERA?

We present a short review of anomalous properties in diffractive photo- and electroproduction of radially excited V(2S) vector mesons. Using the color dipole generalized Balitsky-Fadin-Kuraev-Lipatov phenomenology we analyze anomalous Q ² and energy dependence of the production cross section, V(2S)/V(1S) production ratio, the diffraction slope and anomalous t-behavior of the differential cross section d/dt. The origin of these anomalies is based on the interplay of the nodal structure of V(2S) radial wave function with the energy and dipole size dependence of the dipole cross section and the diffraction slope. We analyze how a different pattern of anomalous behavior of V(2S) production leads to a different position of the node in the wave function and discuss how that node position can be extracted from the data at HERA.