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A quantum memory protocol has been implemented on the basis of the revival of silenced echo (ROSE) in the 167Er3+:Y2SiO5 crystal at the telecommunication wavelength for input light fields with a small number of photons. An efficiency of storage of 44% has been reached at a storage time of 40 μs. The input pulse contains ~340 photons on average, the reconstructed echo signal includes ~150 photons, and the signal-to-noise ratio is 4. It has been shown that the main source of noise is the spontaneous emission of atoms remaining in the excited state because the parameters of two rephasing pulses are imperfect. Methods of increasing the signal-to-noise ratio for the implementation of the efficient quantum memory for single-photon fields have been discussed. [ABSTRACT FROM AUTHOR]

The motion of plasma electrons in a stochastic electromagnetic field is studied in the low-conductivity limit. It is shown that under very general conditions, in the presence of a nonzero average chirality of the small-scale electromagnetic field, the effective current depends on the curl of the applied electric field, j = σE + σ[sub κ] curl E, just as for similar dependences for the electric displacement and magnetic induction vectors in optically active and artificial chiral media. Under certain conditions such an Ohm's law leads to growth of the magnetic field, the structure of the growth being dependent on the conductivity of the medium. [ABSTRACT FROM AUTHOR]

A relation is established between the properties of turbulent flow, the force f[sub 0] setting the fluid in motion, and the spatial r[sub 0] and temporal τ[sub 0] turbulence scales. It is established that the Loıtsyanskiı integral diverges for such turbulence. It is shown that the spectral properties of turbulence depend on the quantity γ=f[sub 0]τ[sub 0][sup 2]/r[sub 0]. The spectrum of turbulent pulsations consists of several universal segments, whose appearance and arrangement depend on γ. It is shown that the parameter Γ=γ[sup 4/3] Re determines the specific dissipation power. The cases of large and small parameters γ and Γ are studied in detail. The physical mechanism leading to “switching off” of dissipation in the limit Γ>1 is determined. © 1998 American Institute of Physics. [ABSTRACT FROM AUTHOR]

A muon spin echo method is proposed for determining the contributions of the static and dynamic local fields in muon experiments. It is shown that if for each muon which has stopped in the sample a rf pulse of fixed duration is applied to the sample at a time τ after the muon entered the sample, then after a sufficient number of muon–positron decays have been accumulated a muon spin echo can appear at time 2τ. © 1996 American Institute of Physics. [ABSTRACT FROM AUTHOR]