Structure in the conductance of normal metal-insulator-metal junctions at very low bias is explained through a nonequilibrium treatment of the tunneling process. In particular, the related peak in the derivative $\frac{d\sigma \mathrm{}\left(V\right)\mathrm{}}{\mathrm{dV}}$ is quantitatively accounted for by the blocking of otherwise available electron tunneling states due to the finite electron relaxation rates in the metal electrodes.

Full dispersion curves, including the effect of retardation, are presented for the coupled optical-phonon—magnetoplasmon surface waves of a degenerate polar semiconductor. The dispersion curves display a surprising amount of interesting new structure which does not occur in the absence of a dc magnetic field.

Using a tunable phonon spectrometer, we have observed phonon emission from films of terbium at 1.6°K. The phonon frequency, 15.15 GHz, was found to be the same as the frequency of an rf magnetic field applied parallel to the surface of the film. This observation provides direct support for the so-called free-lattice model of dynamic magneto-elastic coupling in rare-earth metals.

Nuclear wave functions from recent shell-model calculations are used to evaluate the $log\mathrm{}\left(\mathrm{ft}\right)\mathrm{}$ values relevant to the neutrino absorption cross section of ${}_{}{}^{37}{}_{}{}^{}\mathrm{Cl}$.

We present simple expressions for the differential as well as the total cross sections for multiphoton ionization (of any order) of a one-electron atom with circularly polarized light. We discuss their usefulness in the interpretation of multiphoton ionization experiments.

A first-principles calculation of the field gradient due to conduction electrons in Be leads to a contribution opposite in sign to that from ionic charges, in agreement with expectations from experiment. This result is of particular interest for the theory of nuclear quadrupole coupling constants in metals in view of recent experimental determinations of the sign of the latter.

The observed dependence of Rb fluorescence upon the time after excitation and upon the area of the coherent optical pulse is consistent with quantized electromagnetic field theory and inconsistent with the neoclassical theory of radiation.

Neoclassical transport theory is applied to a plasma in an axisymmetric toroidal magnetic field whose flux surfaces have elliptical cross sections. The contribution of the poloidal field component is important and leads to a large fraction of trapped particles.

A well-defined probability density has been extracted from measured hyperfine frequencies; it corresponds to a pure $|2p〉$ state peaking at a radius of 6.84 Å. The associated wave function is of a dynamic Jahn-Teller type, such that the orbitals $|x+iy〉$, $|x-iy〉$, and $|z〉$ are equally represented. The radiative lifetime calculated from this state agrees well with the experimentally measured one. The probability density also correctly predicts the known resonance linewidths in KI, KBr, and possibly KCl.

Resonance Raman scattering in InSb near the $E_1$ transition has been measured at low temperatures for various different configurations with a tunable dye laser. The experimental curves show a resonance peak at an incident photon energy appreciably higher than the energy of the $E_1$ peak in the reflectivity spectra, contrary to the predictions of existing theories. Double resonance in the Raman tensor involving transitions in the band continuum is proposed to explain the result.

We report the observation of strong nonmonotonic behavior in the photoemission quantum yield of vapor-deposited, amorphous Te films and attribute it to emission from localized states about the bottom of the $d$ conduction band. A theoretical model is proposed which indicates that the observed yield behavior is due to a mobility edge associated with a relatively high proportion of chain-end imperfections which give rise to well-defined localized states in these films.

The electrical conductivity of amorphous Ge films ranging in thickness between 240 Å and 6 μm was measured both in the plane and in the transverse directions. A marked anisotropy in both the resistivity and its temperature dependence was observed below 0.4 μm. There are also marked differences in electrical properties between films deposited at 300°K and kept at 77°K, which are related to the structure of the films.

Tunnel junctions with high concentrations of magnetic atoms at the tunnel barrier show a characteristic conductance quite different from the $G\approx \ln \mathrm{}\left(\right|\mathrm{eV}|+kT)\mathrm{}$ which is shown by low-concentration junctions. The conductance as a function of voltage has a narrow minimum which gets deeper as the temperature is lowered. This is the behavior which is expected to result from interactions making the exchange scattering processes inoperative at low voltages and temperatures.

Hyperfine-field data on actinide impurities in ferromagnetic transition hosts are analyzed in terms of conduction-electron polarization and $d$-electron contributions, except for Np, Pu, and Cm. For these special impurities, it is necessary to invoke the hyperfine-field contribution due to magnetic localized $5f$ shells.

The transition strenth ${\left(h\nu \right)}^2{\epsilon }_2$, computed by Kramers-Kronig analysis of optical reflectance spectra, is compared with x-ray photoelectron spectra for both single-crystal and amorphous ${\mathrm{Sb}}_2$${\mathrm{Se}}_3$. The similarity of the data from x-ray photoelectron spectra for the two modifications suggests that the valence-band structure is essentially the same, whereas differences in the spectral dependence of ${\left(h\nu \right)}^2{\epsilon }_2$ suggest that the conduction-band density of states is lower in the amorphous material, or that the matrix elements for optical transitions are suppressed.

The ultrasonic attenuation coefficient ${\alpha }_k$ has been measured in the paramagnetic phase of Ho in fields from 0 to 50 kG. ${\alpha }_k$ increased as the square of the field and decreased as the temperature increased. A model has been developed which ascribes this increase in ${\alpha }_k$ to the interaction of the longitudinal phonons, via modulation of the exchange interaction, with the spin fluctuations associated with the virtual phase transition at the paramagnetic Curie temperature. This theory also agrees with the velocity data obtained by Moran and Lüthi.

We calculate the critical index $\nu$ of the correlation length between two vertical arrows in the same column for the eight-vertex model and find $\nu =1-\frac{\alpha }{2}$. We also compute at zero temperature the low-lying excitations of the $X-Y-Z$ model.

The electric field gradient in the HD and ${\mathrm{D}}_2$ molecules has been calculated from 87-term wave functions of the James and Coolidge type. With the use of experimental values of the quadrupole interaction constant, the electric quadrupole moment of the deuteron is found to be 0.2875 ${\mathrm{F}}^2$ which is 2% larger than the most recent values. The estimated error is 0.002 ${\mathrm{F}}^2$.

The $g$ factors of the 433-keV $7^{-}$ state and the 439-keV $5^{-}$ state in ${}_{}{}^{210}{}_{}{}^{}\mathrm{Bi}$ which are predominantly ($\pi h_{\frac{9}{2}}$, $\nu g_{\frac{9}{2}}$) have been measured as $g\left(7^{-}\right)=0.302\mathrm{}\pm 0.007$ and $g\left(5^{-}\right)=0.306\mathrm{}\pm 0.009$ by a time-differential method using the reaction ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}({}_{}{}^7{}_{}{}^{}\mathrm{Li},\alpha n){}_{}{}^{210}{}_{}{}^{}\mathrm{Bi}$. From these experimental results, a magnetic moment for the $g_{\frac{9}{2}}$ neutron of $\mu =-(1.33\mathrm{}\pm 0.06){\mu }_N$ [$g\left(\nu g_{\frac{9}{2}}\right)=-0.296\mathrm{}\pm 0.014$] has been deduced. This $g_{\frac{9}{2}}$-neutron magnetic moment is in agreement with the Schmidt value corrected for core polarization.

The elastic scattering of composite projectiles by nuclei is considered in the semiclassical limit. Criteria based on this description are obtained for the incident energy and angular range of data necessary to eliminate discrete ambiguities in optical potentials for such projectiles. We demonstrate the effectiveness of these criteria for elastic $\alpha$-scattering data.