The effect of atomic binding on a nuclear resonance

A recent analysis of a sharp (γ ≈ 1.6 keV) resonance in the ¹²C(p,p)¹²C reaction interprets 0.6 keV of the width as an atomic effect associated with excitation of the final atom. We describe a simpler, almost kinematic, atomic effect, viz. the smearing of the relative velocity of incident proton and target nucleus by the velocity distribution of the nucleus in the initial atom. While reproducing about the same broadening, this approach differs from the previous one in all other aspects.     

Spin-torque ferromagnetic resonance induced by the spin Hall effect

We demonstrate that the spin Hall effect in a thin film with strong spin-orbit scattering can excite magnetic precession in an adjacent ferromagnetic film. The flow of alternating current through a Pt/NiFe bilayer generates an oscillating transverse spin current in the Pt, and the resultant transfer of spin angular momentum to the NiFe induces ferromagnetic resonance dynamics. The Oersted field from the current also generates a ferromagnetic resonance signal but with a different symmetry. The ratio of these two signals allows a quantitative determination of the spin current and the spin Hall angle.     

The cumulative resonance in atomic ground state induced by modulated light field

The interaction of an atomic system with a light beam, intensity-modulated at the ground-state Zeeman frequency is analysed by the dressed-atom method. When the light field is resonant, this interaction produces a new type of degereracy of dressed-atom energy levels which is not of level crossing type. This gives rise to the cumulative resonance with a width depending on the light intensity.     

一种新型原子共振滤光器研究

报道Rb原子法拉弟共振滤光器(AFROF)的理论与实验研究.考虑Rb原子超精细结构的塞曼效应,对Rb-AFROF的传输特性进行理论分析,实验观测了Rb-AFROF的工作频率、通带宽度随外磁场和气室温度的变化关系.测量表明,Rb-AFROF传输效率～50%,带宽小于3GHz,最小探测光强～0.1μW.     

Electromagnetic waves in a magnetoactive fluctuating plasma

Radiophysics and Electronics Institute, Academy of Sciences of the USSR. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 32, No. 1, pp. 27–33, January, 1989.     

The effect of excited atomic states on the harmonic generation in a photoionized plasma

Owing to the conservation by the electrons of the memory of their intra-atomic states, a photoionized plasma arising in the mode of suppression of the ionization barrier exhibits a pronounced dependence of the efficiency of generation of the third and fifth harmonics of the pumping field on such states of electrons. For the maximal values of generation efficiency, this dependence is directly proportional to the tenth power of the principal quantum number of excited ns states of electrons.     

Magnetic resonance in an atomic vapor excited by a mechanical resonator

We demonstrate a direct resonant interaction between the mechanical motion of a mesoscopic resonator and the spin degrees of freedom of a sample of neutral atoms in the gas phase. This coupling, mediated by a magnetic particle attached to the tip of the miniature mechanical resonator, excites a coherent precession of the atomic spins about a static magnetic field. The novel coupled atom-resonator system may enable development of low-power, high-performance sensors, and enhance research efforts connected with the manipulation of cold atoms, quantum control, and high-resolution microscopy.     

Inversion of atomic resonance transitions by electron collisional dissociation

Population inversion of several resonance transitions in the rare-earth atom thulium has been achieved by electron collisional dissociation of TmI₃ molecules in a fast electric discharge configuration. The inversion manifests itself by a strong spiking behavior during the initial current rise and lasts for several nanoseconds. Results of a model calculation of this inversion process for resonance lines support our experimental findings.     

Study of the CdS crystal evaporation kinetics by laser step atomic photoionization

Laser resonant multistep atomic photoionization is employed to measure evaporation rates and saturated vapor pressures of cadmium sulfide and pure cadmium in temperature ranges of 585–950 and 350–535 K, respectively. It is shown that CdS thermally dissociates into Cd atoms and S₂ molecules. The photoionization of cadmium atoms follows the scheme

$5s^1 S_0 \xrightarrow{{\lambda _1 = 326.1nm}}5p^3 P_1 \xrightarrow{{\lambda _2 = 479.9nm}}6s^3 S_1 \xrightarrow{{\lambda _3 = 488.1nm}}17p^3 P_2 + (\varepsilon = 12kV/cm) \to Cd^ + + e^ - .$

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The minimal pressure of pure cadmium is found to be 10^?11 mm Hg.     

Efficient transfer of light energy to a nanoparticle by means of a resonance atomic lens

A cascade transfer of light energy to a resonance atom situated near a spherical nanoparticle and then, by a nonradiative mechanism, to the nanoparticle itself is considered. It is established that the efficiency of the cascade transfer essentially depends on the frequency and polarization of light, on the distance between the atom and the particle, on the optical properties of the particle, and on the time conditions of radiation. The rate of light absorption by a metal nanoparticle via cascade energy transfer may be 10⁴–10⁵ times higher than the direct absorption of light by a nanoparticle. For a fixed frequency of light, the cascade transfer of energy is a sharply selective function of the distance between the atom and the particle (the resonance width is about 10^?2 of the particle radius). Atomic fluorescence exhibits similar behavior. This feature can form the basis for a new method of optical scanning microscopy and location and localization of atoms near the surface of a particle.     

Two photon photoelectric effect in the surface plasma resonance of aluminium

Photoemission from Al films is observed at a photon energy of 2.6 eV in an ATR-experiment. The yield is proportional to the square of the light intensity. Resonances occur at angles corresponding to surface plasma resonances of the fundamental and double frequency.