# Showing papers in "Physical Review Letters in 1970"

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Bell Labs

^{1}TL;DR: In this paper, it is hypothesized that similar acceleration and trapping are possible with atoms and molecules using laser light tuned to specific optical transitions, and the implications for isotope separation and other applications of physical interest are discussed.

Abstract: Micron-sized particles have been accelerated and trapped in stable optical potential wells using only the force of radiation pressure from a continuous laser. It is hypothesized that similar accelerations and trapping are possible with atoms and molecules using laser light tuned to specific optical transitions. The implications for isotope separation and other applications of physical interest are discussed.

4,516 citations

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TL;DR: In this article, the dielectric correlation function in glasses is calculated and the assumption of short correlation length for normal modes breaks the momentum selection rules and leads to expressions for the first-order Raman-scattering intensity in terms of the density-of-state functions and known frequency-dependent amplitudes.

Abstract: We present a calculation of the dielectric correlation function in glasses showing how the assumption of short correlation length for normal modes breaks the momentum selection rules and leads to expressions for the first-order Raman-scattering intensity in terms of the density-of-states functions and known frequency-dependent amplitudes

971 citations

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TL;DR: Simultaneity in optical photon pairs parametric production, verifying quantum mechanical description of fluorescence is discussed in this paper. But it is not discussed in detail in this paper..

Abstract: Simultaneity in optical photon pairs parametric production, verifying quantum mechanical description of fluorescence

966 citations

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TL;DR: In this article, the Schrodinger-type equation for odd-parity perturbations on a background geometry has been extended to the even-PARITY perturbation, which should greatly simplify the analysis for calculations of gravitational radiation from stars and from objects falling into black holes.

Abstract: The Schr\"odinger-type equation for odd-parity perturbations on a background geometry has been extended to the even-parity perturbations. This should greatly simplify the analysis for calculations of gravitational radiation from stars and from objects falling into black holes.

918 citations

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TL;DR: In this article, the production process of large-mass lepton pairs from hadron-hadron inelastic collisions in the limiting region is considered, and general scaling properties and connections with deep electron scattering are discussed.

Abstract: On the basis of a parton model studied earlier we consider the production process of large-mass lepton pairs from hadron-hadron inelastic collisions in the limiting region, $s\ensuremath{\rightarrow}\ensuremath{\infty}$, $\frac{{Q}^{2}}{s}$ finite, ${Q}^{2}$ and $s$ being the squared invariant masses of the lepton pair and the two initial hadrons, respectively. General scaling properties and connections with deep inelastic electron scattering are discussed. In particular, a rapidly decreasing cross section as $\frac{{Q}^{2}}{s}\ensuremath{\rightarrow}1$ is predicted as a consequence of the observed rapid falloff of the inelastic scattering structure function $\ensuremath{
u}{W}_{2}$ near threshold.

904 citations

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TL;DR: Eilenberger's transportlike equations for a superconductor of type II can be simplified very much in the dirty limit, and a diffusionlike equation is derived which is the generalization of the de Gennes-Maki theory for dirty superconductors to arbitrary values of the order parameter.

Abstract: Eilenberger's transportlike equations for a superconductor of type II can be simplified very much in the dirty limit. In this limit a diffusionlike equation is derived which is the generalization of the de Gennes-Maki theory for dirty superconductors to arbitrary values of the order parameter.

858 citations

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TL;DR: In this article, four-photon stimulated scattering has been observed in borosilicate glass under high-power 5300-AA{} picosecond-pulse excitation.

Abstract: Four-photon stimulated scattering has been observed in borosilicate glass under high-power 5300-\AA{} picosecond-pulse excitation. Parametric emission is generated from 4000 to 7000 \AA{} from filaments formed in the glass, the wavelength depending on the emission angle.

759 citations

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TL;DR: In this paper, small-scale filaments were observed in calcite, quartz, sodium chloride, and several glasses under picosecond pulse excitation, and the physical mechanism responsible for these processes is the change in refractive index resulting from electronic distortion.

Abstract: Frequency broadening and small-scale filaments were observed in calcite, quartz, sodium chloride, and several glasses under picosecond pulse excitation. The physical mechanism responsible for these processes is the change in refractive index resulting from electronic distortion.

690 citations

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TL;DR: In this article, the concepts of irreducible mass and reversible and irreversible transformations in black holes are introduced, leading to the formula (E}^{2}=m{\mathrm{ir}}^{2}) +{p}^{ 2}$ for a black hole of linear momentum $p$ and angular momentum $L$.

Abstract: The concepts of irreducible mass and of reversible and irreversible transformations in black holes are introduced, leading to the formula ${E}^{2}=m_{\mathrm{ir}}^{2}+(\frac{{L}^{2}}{4m_{\mathrm{ir}}^{2}})+{p}^{2}$ for a black hole of linear momentum $p$ and angular momentum $L$.

593 citations

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TL;DR: In this paper, it is suggested that the property of nonclassical rotational inertia possessed by superfluid liquid helium may be shared by some solids, in particular if the solid is Bose-condensed as recently proposed by Chester.

Abstract: It is suggested that the property of nonclassical rotational inertia possessed by superfluid liquid helium may be shared by some solids. In particular, nonclassical rotational inertia very probably occurs if the solid is Bose-condensed as recently proposed by Chester. Anomalous macroscopic effects are then predicted. However, the associated superfluid fraction is shown to be very small (probably $\ensuremath{\lesssim}{10}^{\ensuremath{-}4}$) even at $T=0$, so that these effects could well have been missed. Direct tests are proposed.

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TL;DR: In this article, the formation and propagation of ion-acoustic solitons are observed experimentally and the character of a solitary pulse is observed to follow the predictions of the Kortewegde Vries equation with respect to the shape and velocity of the soliton.

Abstract: The formation and propagation of ion-acoustic solitons are observed experimentally. The character of a solitary pulse is observed to follow the predictions of the Kortewegde Vries equation with respect to the shape and velocity of the soliton. The interaction between two solitons is modified significantly by dissipation. However, the nonlinear nature of the interactions is confirmed for solitons moving in the same direction. Solitons moving in the opposite direction and colliding have very little effect on each other.

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TL;DR: In this paper, it was suggested that if the structure function for deep inelastic electron-proton scattering behaves near threshold as the elastic electromagnetic form factor of the proton, then the elastic form factor behaves for large momentum transfers as the energy waveform factor of a proton.

Abstract: It is suggested that if the structure function $\ensuremath{
u}{W}_{2}$ for deep inelastic electron-proton scattering behaves near threshold as $\ensuremath{
u}{W}_{2}\ensuremath{\sim}(\frac{1}{\ensuremath{\omega}}){(1\ensuremath{-}\frac{1}{\ensuremath{\omega}})}^{p} \mathrm{for} \ensuremath{\omega}\ensuremath{\equiv}\frac{2M\ensuremath{
u}}{{Q}^{2}}\ensuremath{\rightarrow}1,$ then the elastic electromagnetic form factor of the proton ${F}_{1}$ behaves for large momentum transfers as ${F}_{1}({Q}^{2})\ensuremath{\sim}{(\frac{1}{{Q}^{2}})}^{\frac{(p+1)}{2}} \mathrm{for} {Q}^{2}\ensuremath{\rightarrow}\ensuremath{\infty}$

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TL;DR: Drift mobility and conductivity measurements were made between 290 and 85 K on amorphous silicon specimens prepared by glow-discharge decomposition of silane as mentioned in this paper, and the results suggest that excess electrons drift in the extended states with a mobility of about 10

Abstract: Drift mobility and conductivity measurements were made between 290 and 85\ifmmode^\circ\else\textdegree\fi{}K on amorphous silicon specimens prepared by glow-discharge decomposition of silane. The results suggest that excess electrons drift in the extended states with a mobility of about 10 ${\mathrm{cm}}^{2}$ ${\mathrm{sec}}^{\ensuremath{-}1}$ ${\mathrm{V}}^{\ensuremath{-}1}$. At lower temperatures, phonon-assisted hopping occurs through localized states occupying a range of 0.2 eV below the extended states. Conductivity results also suggest hopping transport near the Fermi energy.

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TL;DR: In this article, a substantial part of the observed behavior of inelastic electron-proton scattering is due to a non-fractured component of virtual photon proton scattering.

Abstract: We propose that a substantial part of the observed behavior of inelastic electron-proton scattering is due to a nondiffractive component of virtual photon-proton scattering. The behavior of resonance electroproduction is shown to be related in a striking way to that of deep inelastic electron-proton scattering. We derive relations between the elastic and inelastic form factors and the threshold behavior of the inelastic structure functions in the scaling limit.

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TL;DR: In this paper, the authors considered the evolution of an elongated rotating configuration by gravitational radiation and the possibility of a secular instability being induced by it, in the context of the classical homogeneous figures of Maclaurin and Jacobi.

Abstract: The evolution of an elongated rotating configuration by gravitational radiation and the possibility of a secular instability being induced by it are considered in the context of the classical homogeneous figures of Maclaurin and Jacobi. The triaxial Jacobian ellipsoid evolves in the direction of increasing angular velocity and approaches (exponentially) the point of bifurcation where it ceases to radiate. Further, radiation reaction does not make the Maclaurin spheroid secularly unstable past the point of bifurcation.

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Bell Labs

^{1}TL;DR: In this paper, the authors show that the semiconductor-to-metal transition in Sm chalcogenides occurs discontinuously at 6.5 kbar at room temperature, whereas such a transition takes place continuously over a broad pressure range in SmTe and SmSe.

Abstract: Resistivity and lattice-constant measurements under high pressure on SmS show that a $4f\ensuremath{\rightarrow}5d$ electronic transition in SmS occurs discontinuously at 6.5 kbar at room temperature, whereas such a transition takes place continuously over a broad pressure range in SmTe and SmSe. The pressure-induced semiconductor-to-metal transition in the Sm chalcogenides and their pressure-volume relationship are consistent with the conversion of ${\mathrm{Sm}}^{2+}$ to ${\mathrm{Sm}}^{3+}$. Optical-absorption measurements in these materials correlate well with the resistivity data under pressure. The semiconductor-to-metal transition in Sm chalcogenides appears to fit the model recently proposed by Falicov and Kimball for a system with a localized state and a conduction band.

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TL;DR: In this article, the observed degeneracy of mutually exclusive infrared and Raman-active modes in Mo$(S) was traced to the weak van der Waals interaction between layers.

Abstract: The observed degeneracy of mutually exclusive infrared- and Raman-active modes in Mo${\mathrm{S}}_{2}$ is traced by means of group theory to the weak van der Waals interaction between layers.

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TL;DR: In this article, the asymptotic time behavior of the velocity autocorrelation function and of the kinetic parts of the correlation functions for the shear viscosity and the heat conductivity is derived.

Abstract: The asymptotic time behavior of the velocity autocorrelation function and of the kinetic parts of the correlation functions for the shear viscosity and the heat conductivity is derived. The results are expressed in terms of the transport coefficients and the specific heats and are valid for all densities.

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TL;DR: In this article, the authors have observed a divergence of the magnetic birefringence, and a critical increase and slowing of the fluctuations in order in the isotropic phase of a nematic liquid crystal.

Abstract: We have observed a divergence of the magnetic birefringence, and a critical increase and slowing of the fluctuations in order in the isotropic phase of a nematic liquid crystal. Our results are quantitatively described by a mean-field model except for a critical region close to the ordering temperature where the fluctuations are so large that the meanfield approximation fails.

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TL;DR: The two-fluid critical mixing point in this article occurs at the intersection of three lines of critical points, in a suitable variable space, and a free energy function is proposed which removes certain discrepancies between classical (Landau) theory and experimental thermodynamic measurements.

Abstract: The two-fluid critical mixing point in ${\mathrm{He}}^{3}$ - ${\mathrm{He}}^{4}$ differs from ordinary critical points in that it occurs at the intersection of three lines of critical points, in a suitable variable space. A free-energy function is proposed which removes certain discrepancies between classical (Landau) theory and experimental thermodynamic measurements. Certain solid-state transitions (e.g., the metamagnetic-antiferromagnetic transition in Fe${\mathrm{Cl}}_{2}$) are thermodynamic analogs of critical mixing in ${\mathrm{He}}^{3}$ - ${\mathrm{He}}^{4}$.

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TL;DR: In this article, the authors give a general argument for the occurrence of the second transition in the lattice gas, plus explicit results for one-dimensional fluid models with two first-order transitions.

Abstract: For a fluid in which the interaction potential has a hard core plus a negative part, softening of the hard core can produce a second transition if a first already exists. We give a general argument for the occurrence of the second transition in the lattice gas, plus explicit results for one-dimensional fluid models with two first-order transitions. One such model also provides an example of the breakdown of the law of rectilinear diameters.

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Bell Labs

^{1}TL;DR: In this article, the authors measured optical absorption and magnetic susceptibility of amorphous materials as a function of temperature and found an exponential variation of absorption constant with photon energy in the range $0.09l\ensuremath{αl0.5$

Abstract: We measured optical absorption and magnetic susceptibility of amorphous ${\mathrm{As}}_{2}$${\mathrm{S}}_{3}$ as a function of temperature. An exponential variation of absorption constant with photon energy was found in the range $0.09l\ensuremath{\alpha}l0.5$ ${\mathrm{cm}}^{\ensuremath{-}1}$. A Curie term in the susceptibility was shown to be characteristic of disorder in the vitreous material. A model relating the weak absorption tail to the susceptibility requires highly localized states having an exponential energy distribution in the gap.

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Bell Labs

^{1}TL;DR: In this paper, the saturated value of the radiation pressure force on neutral atoms is used to produce a constant central force field to deflect atoms in circular orbits and make a high-resolution velocity analyzer.

Abstract: It is proposed to use the saturated value of the radiation pressure force on neutral atoms to produce a constant central force field to deflect atoms in circular orbits and make a high-resolution velocity analyzer. This is useful for studying the interaction of atoms with high-intensity monochromatic light, and to separate, velocity analyze, or trap neutral atoms of specific isotopic species or hyperfine level.

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TL;DR: In this paper, a high-resolution electron-impact spectrometer was used to study the scattering of electrons from surfaces of ZnO single crystals in ultrahigh vacuum with a high resolution electron impact spectrometers.

Abstract: Scattering of electrons from surfaces of ZnO single crystals has been studied in ultrahigh vacuum with a high-resolution electron-impact spectrometer ($\ensuremath{\Delta}El20$ meV, impact energy ${E}_{0}=1\ensuremath{-}100$ eV). The energy-loss spectrum in specular reflection shows a series of equally spaced loss peaks. The characteristic loss energies [68.8 meV for the ($1\overline{1}00$) surface and 67.3 meV for the (0001) and the ($000\overline{1}$) surfaces] agree with the energies of optical surface phonons determined by the condition $\mathrm{Re}{\ensuremath{\epsilon}}_{n}(\ensuremath{\omega})=\ensuremath{-}1$.

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TL;DR: In this article, a phenomenological model of electron-proton scattering is developed which can account for the general qualitative and quantitative features of the data and some interesting links between the elastic and inelastic form factors are discussed.

Abstract: A phenomenological model of electron-proton scattering is developed which can account for the general qualitative and quantitative features of the data. Some interesting links between the elastic and inelastic form factors are discussed.

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TL;DR: The early history of the universe is discussed in the context of an exponentially rising density of particle states in this article, where the early history was discussed in terms of an exponential scaling of the number of states in the universe.

Abstract: The early history of the universe is discussed in the context of an exponentially rising density of particle states

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TL;DR: Magnetic field splitting of the quasiparticle energy states in superconducting aluminum films has been observed in a tunneling experiment as discussed by the authors, and the magnitude of the splitting was found to be $2.

Abstract: Magnetic field splitting of the quasiparticle energy states in superconducting aluminum films has been observed in a tunneling experiment. The magnitude of the splitting was found to be $2\ensuremath{\mu}H$, and is attributed to the magnetic moment of the quasiparticles. The observed tunneling conductance is in qualitative agreement with theory.