The Nature of Electronic Charge

Advances in gauge theories and unified theories have not thrown light on the meaning of electron. The problem of the origin of electronic charge is made precise, new insights gained from Weyl space are summarized, and the origin of charge in terms of fractional spin is suggested. A new perspective on the abelian Chern-Simons theory is presented to explain charge.     

采用级联原子滤光器的新型卫星激光链路系统研究

提出级联佛克脱型原子滤光器(Linked VADOF)的新构想。从理论上分析并计算了级联佛克脱型原子滤光器的透射谱。结果表明，级联佛克脱型原子滤光器将佛克脱型原子滤光器的多峰改造为单峰结构，具有比佛克脱型原子滤光器更窄的线宽和更高的噪声抑制比。将这种新型结构应用于激光信标锁频。该锁频方案提高了信标光频率的稳定性。在此基础上，给出了发射端采用级联佛克脱型原子滤光器锁频，接收端采用法拉第型原子滤光器(FADOF)滤光的新型卫星激光链路系统。外场初步联调实验表明了该系统的可行性。     

Diffusion in three-dimensional random systems at their percolation thresholds

Extensive Monte Carlo simulations of theant-in-the-labyrinth problem on randomL* L* L simple cubic lattices are performed, forL up to 960 on a CRAY-YMP supercomputer. The exponentk for the rms displacementr witht inrt ^k is found to bek=0.190±0.003. As a second approach, large percolation clusters with chemical shells up to 300 are generated on a simple cubic lattice at criticality. The diffusion equation is then solved by using the exact enumeration technique. The corresponding critical exponentd ^w is found to be 1/d ^w =0.250±0.003.On leave from I. Institut für Theoretische für Physik, Universität Hamburg, D-2000 Hamburg, Federal Republic of Germany.     

A new class of long-tailed pausing time densities for the CTRW

We present some asymptotic results for the family of pausing time densities having the asymptotic (t) property(t) [t ln¹⁺(t/T)]^–1. In particular, we show that for this class of pausing time densities the mean-squared displacement r ²(t) is asymptotically proportional to ln(t/T), and the asymptotic distribution of the displacement has a negative exponential form.     

Measurement of Diffusion in Zeolites—A Never Ending Challenge?

A review is given on the main problems associated with the determination and interpretation of molecular diffusion in zeolites. It is shown that the diffusivities may most decisively depend on the relevant space and time scales of observation, as well as on the physical state under which the measurements are carried out. Special emphasis is given to the microscopic techniques and their most recent evidence on the existence of transport resistances distributed over the intracrystalline space.     

Anomalously high heat capacity of liquids: relation to structural properties

ABSTRACT

Heat capacity of several liquids which demonstrate anomalous behaviour is studied. It is shown that isochoric heat capacity of these liquids shows anomalously high values which is related to smooth structural crossover in these liquids. This phenomenon can be used for qualitative explanation of high heat capacity of water and some other substances.     

Muon g-2 discrepancy:new physics or a relatively light Higgs?

After a brief review of the muon g-2 status,we discuss hypothetical errors in the Standard Model prediction that might explain the present discrepancy with the experimental value.None of them seems likely.In particular,a hypothetical increase of the hadroproduction cross section in low-energy e+e-collisions could bridge the muon g-2 discrepancy,but it is shown to be unlikely in view of current experimental error estimates.If,nonetheless,this turns out to be the explanation of the discrepancy,then the 95% CL upper bound on the Higgs boson mass is reduced to about 135 GeV which,in conjunction with the experimental 114.4 GeV 95%CL lower bound,leaves a narrow window for the mass of this fundamental particle.     

Tb doping induced enhancement of anomalous Hall effect in NiFe films

Tbx(Ni0.8Fe0.2)1-x films with x≤0.14 are fabricated and the anomalous Hall effect is studied.The intrinsic anomalous Hall conductivity and the extrinsic one from the impurity and phonon induced scattering both increase with increasing x.The enhancement of the intrinsic anomalous Hall conductivity is ascribed to both the weak spin–orbit coupling enhancement and the Fermi level shift.The enhancement of the extrinsic term comes from the changes of both Fermi level and impurity distribution.In contrast,the in-plane and the out-of-plane uniaxial anisotropies in the Tb Ni Fe films change little with x.The enhancement of the Hall angle by Tb doping is helpful for practical applications of the Hall devices.     

A Continuous-Time Random Walk Extension of the Gillis Model

We consider a continuous-time random walk which is the generalization, by means of the introduction of waiting periods on sites, of the one-dimensional non-homogeneous random walk with a position-dependent drift known in the mathematical literature as Gillis random walk. This modified stochastic process allows to significantly change local, non-local and transport properties in the presence of heavy-tailed waiting-time distributions lacking the first moment: we provide here exact results concerning hitting times, first-time events, survival probabilities, occupation times, the moments spectrum and the statistics of records. Specifically, normal diffusion gives way to subdiffusion and we are witnessing the breaking of ergodicity. Furthermore we also test our theoretical predictions with numerical simulations.     

Anomalous Hall effect of heavy holes in III-V semiconductor quantum wells

The anomalous Hall effect of heavy holes in semiconductor quantum wells is studied in the intrinsic transport regime, where the Berry curvature governs the Hall current properties. Based on the first--order perturbation of wave function the expression of the Hall conductivity the same as that from the semiclassical equation of motion of the Bloch particles is derived. The dependence of Hall conductivity on the system parameters is shown. The amplitude of Hall conductivity is found to be balanced by a competition between the Zeeman splitting and the spin--orbit splitting.