Showing papers in "Physical Review Letters in 1972"
TL;DR: In this paper, the temporal correlations of thermodynamic concentration fluctuations have been measured in a chemically reactive system at equilibrium by observing fluctuations of the fluorescence of a reaction product, and the experiment yields the chemical rate constants and diffusion coefficients and shows the coupling among them.
Abstract: The temporal correlations of thermodynamic concentration fluctuations have been measured in a chemically reactive system at equilibrium by observing fluctuations of the fluorescence of a reaction product. The experiment yields the chemical rate constants and diffusion coefficients and shows the coupling among them. Data are reported for binding of ethidium bromide to DNA.
1,733 citations
TL;DR: In this paper, the linear polarization correlation of the photons emitted in an atomic cascade of calcium was measured and it was shown by a generalization of Bell's inequality that the existence of local hidden variables imposes restrictions on this correlation in conflict with the predictions of quantum mechanics.
Abstract: We have measured the linear polarization correlation of the photons emitted in an atomic cascade of calcium. It has been shown by a generalization of Bell's inequality that the existence of local hidden variables imposes restrictions on this correlation in conflict with the predictions of quantum mechanics. Our data, in agreement with quantum mechanics, violate these restrictions to high statistical accuracy, thus providing strong evidence against local hidden-variable theories.
1,482 citations
TL;DR: In this article, the unconstrained dynamical degrees of freedom of the gravitational field are identified with the conformally invariant three-geometries of spacelike hypersurfaces.
Abstract: The unconstrained dynamical degrees of freedom of the gravitational field are identified with the conformally invariant three-geometries of spacelike hypersurfaces. New results concerning the action principle, choice of canonical variables, and initial-value equations strengthen this identification. One of the new canonical variables is shown to play the role of "time" in the formalism.
1,311 citations
TL;DR: In this paper, the critical exponents for dimension $d = 4, where d is the dimension of the dimension in the dimension space of the model, with the exponent of the critical exponent being $1+\frac{1.6} for an Ising-like model and $1 +\frac {1.5} for a more complex model.
Abstract: Critical exponents are calculated for dimension $d=4\ensuremath{-}\ensuremath{\epsilon}$ with $\ensuremath{\epsilon}$ small, using renormalization-group techniques. To order $\ensuremath{\epsilon}$ the exponent $\ensuremath{\gamma}$ is $1+\frac{1}{6}\ensuremath{\epsilon}$ for an Ising-like model and $1+\frac{1}{5}\ensuremath{\epsilon}$ for an $\mathrm{XY}$ model.
1,271 citations
TL;DR: In this paper, a detailed scaling theory for critical point shift and rounding in films of finite thickness is proposed, which is confirmed by exact calculations on $d$-dimensional ferromagnetic spherical models and ideal Bose fluids with various boundary conditions.
Abstract: Critical phenomena in films of finite thickness are considered. A detailed scaling theory, with allowance for distinct exponents $\ensuremath{\lambda}$ and $\ensuremath{\theta}=\frac{1}{\ensuremath{
u}}$ for the critical-point shift and rounding, respectively, is confirmed by exact calculations on $d$-dimensional ferromagnetic spherical models and ideal Bose fluids with various boundary conditions. Isingmodel results and existing data on real helium films are consistent with the theory.
1,052 citations
TL;DR: In this article, the critical exponents for a $d$-dimensional system with an isotropic $n$-component order parameter and long-range attractive interactions are derived, using the renormalization group approach.
Abstract: Critical exponents for a $d$-dimensional system with an isotropic $n$-component order parameter and long-range attractive interactions decaying as $\frac{1}{{r}^{d+\ensuremath{\sigma}}} (\ensuremath{\sigma}g0)$ are derived, using the renormalization group approach, as power series in $\ensuremath{\epsilon}=2\ensuremath{\sigma}\ensuremath{-}dg0$ ($\ensuremath{\sigma}\ensuremath{
e}2$, fixed) or $\ensuremath{\Delta}\ensuremath{\sigma}=\ensuremath{\sigma}\ensuremath{-}\frac{1}{2}dg0$ ($d$ fixed) and, separately, to order $\frac{1}{n}$ for all $d$ and $\ensuremath{\sigma}\ensuremath{
e}2$. For $\ensuremath{\epsilon}l0$ the exponents have fixed ("classical") values; when $\ensuremath{\epsilon}=\ensuremath{\Delta}\ensuremath{\sigma}=0$ fractional powers of $\mathrm{ln}(\frac{\ensuremath{\Delta}T}{{T}_{c}})$ appear; when $\ensuremath{\sigma}g2$ the exponents assume their short-range values.
878 citations
TL;DR: In this paper, separate wave equations with source terms are presented for electromagnetic and gravitational perturbations of an uncharged, rotating black hole, which describe the radiative field completely, and also part of the non-radiative field.
Abstract: Separable wave equations with source terms are presented for electromagnetic and gravitational perturbations of an uncharged, rotating black hole. These equations describe the radiative field completely, and also part of the nonradiative field. Nontrivial, source-free, stationary perturbations are shown not to exist. The barrier integral governing synchrotron radiation from particles in circular orbits is shown to be the same as for scalar radiation. Future applications (stability of rotating black holes, "spin-down," superradiant scattering, floating orbits) are outlined.
857 citations
TL;DR: This article showed that elastic strain energy may account for the tendency of some nematic liquid crystals to lie parallel to the direction of rubbing on a solid surface that has been slightly deformed by rubbing, or perpendicular to a surface that is slightly rough in two dimensions.
Abstract: We show that elastic strain energy may account for the tendency of some nematic liquid crystals to lie parallel to the direction of rubbing on a solid surface that has been slightly deformed by rubbing, or perpendicular to a surface that is slightly rough in two dimensions.
782 citations
TL;DR: In this article, numerical simulations of three-dimensional homogeneous isotropic turbulence at wind-tunnel Reynolds numbers are presented, and the results of the simulations are compared with the predictions of the direct-interaction turbulence theory.
Abstract: This Letter reports numerical simulations of three-dimensional homogeneous isotropic turbulence at wind-tunnel Reynolds numbers. The results of the simulations are compared with the predictions of the direct-interaction turbulence theory.
528 citations
TL;DR: In this article, the theory of the three-wave parametric instability for weakly inhomogeneous media is derived with an application to laser pellet irradiation and applied to laser beamforming.
Abstract: The theory of the three-wave parametric instability for weakly inhomogeneous media is derived with an application to laser pellet irradiation.
496 citations
TL;DR: The critical exponents of generalized classical Heisenberg models with $n$ internal degrees of freedom as an exact expansion were computed in this article for the Ising case, and the results to this order for the three-dimensional Ising cases were shown to be 1.244 and 0.037, respectively.
Abstract: The critical exponents $\ensuremath{\gamma}$, $\ensuremath{\eta}$ and the "crossover index" $\ensuremath{\phi}$ are computed for generalized classical Heisenberg models with $n$ internal degrees of freedom as an exact expansion in $\ensuremath{\epsilon}=4\ensuremath{-}d$ ($d$ is the number of space dimensions). Results are obtained to order ${\ensuremath{\epsilon}}^{2}$ for $\ensuremath{\gamma}$ and to order ${\ensuremath{\epsilon}}^{3}$ for $\ensuremath{\eta}$. The results to this order for the three-dimensional Ising case ($n=\ensuremath{\epsilon}=1$) are $\ensuremath{\gamma}=1.244$ and $\ensuremath{\eta}=0.037$.
TL;DR: A simple theory for calculating the electron-phonon coupling constant was developed in this article, where a simple theory was developed for computing the electron ϵ = ε √ √ ε.
Abstract: A simple theory is developed for calculating the electron-phonon coupling constant $\ensuremath{\lambda}$
TL;DR: In this paper, the melting pressure of a sample of a solid containing less than 40ppm of impurities, self-cooled to below 2 mK in a Pomeranchuk compression cell, indicates the existence of a new phase in solid materials below 2.7 mK of a fundamentally different nature than the anticipated antiferromagnetic ordered state.
Abstract: Measurements of the melting pressure of a sample of ${\mathrm{He}}^{3}$ containing less than 40-ppm ${\mathrm{He}}^{4}$ impurities, self-cooled to below 2 mK in a Pomeranchuk compression cell, indicate the existence of a new phase in solid ${\mathrm{He}}^{3}$ below 2.7 mK of a fundamentally different nature than the anticipated antiferromagnetically ordered state. At lower temperatures, evidence of possibly a further transition is observed. We discuss these pressure measurements and supporting temperature measurements.
TL;DR: In this article, the authors examined the effects of compositional variation on the distribution of states in amorphous semiconductors and predicted that an Anderson transition will occur in the band of lone-pair states when a group-VI element is added to a tetrahedral amorphized semiconductor.
Abstract: The origin of electronic states in two classes of semiconductors is explored: (i) semiconductors containing group-VI elements in twofold coordination, and (ii) tetrahedral semiconductors. In the first case the valence band arises from the unshared electron pair (lone pair) of the group-VI atom. We examine the effects of compositional variation on the distribution of states in amorphous semiconductors. It is predicted that an Anderson transition will occur in the band of lone-pair states when a group-VI element is added to a tetrahedral amorphous semiconductor.
TL;DR: In this paper, the authors construct unified models of weak and electromagnetic interactions using just three gauge fields which correspond to the intermediate vector boson and the photon, and do not predict processes involving neutral lepton currents.
Abstract: We construct unified models of weak and electromagnetic interactions using just three gauge fields which correspond to the intermediate vector boson and the photon. These models may be renormalizable, and do not predict processes involving neutral lepton currents.
TL;DR: In this paper, the authors investigated the ac conductivity of glasses due to atomic and electronic hopping between sites with random space and energy separations and found that glassy materials should quite generally exhibit a nearly linear conductivity-frequency relationship.
Abstract: We investigate the ac conductivity of glasses due to atomic and electronic hopping between sites with random space and energy separations. Several examples are considered including the structural model of glasses recently introduced by Anderson, Halperin, and Varma, and by Philips. We find that glassy materials should quite generally exhibit a nearly linear conductivity-frequency relationship. The details of any particular conductivity mechanism should be contained in the deviation from linearity.
TL;DR: In this paper, the effects of the nonlinearity of the large-amplitude plasma wave and the inhomogeneity of the plasma, on the excitation of the wave by beating two laser beams were analyzed.
Abstract: We analyze the effects of (i) the nonlinearity of the large-amplitude plasma wave, and (ii) the inhomogeneity of the plasma, on the excitation of the plasma wave by beating two laser beams.
TL;DR: In this paper, it was pointed out that the measurement of the deceleration parameter by Sandage (1972) implies an upper limit of a few tens of electron volts on the sum of the masses of all the possible light, stable particles that interact only weakly.
Abstract: It is pointed out that the measurement of the deceleration parameter by Sandage (1972) implies an upper limit of a few tens of electron volts on the sum of the masses of all the possible light, stable particles that interact only weakly. In the discussion of the problem, it is assumed that the universe is expanding from an initially hot and condensed state as envisaged in the 'big-bang' theories.
TL;DR: In this article, the transition from ballistic to second sound to diffusive propagation of heat pulses in the semimetal bismuth in the temperature range of 1.2 to 4.0 K was observed.
Abstract: We have observed the transition from ballistic to second sound to diffusive propagation of heat (phonon) pulses in the semimetal bismuth in the temperature range of 1.2 to 4.0 K. The saturated second-sound velocity is found to be independent of orientation and has a a value of (0.78\ifmmode\pm\else\textpm\fi{}0.05)\ifmmode\times\else\texttimes\fi{}${10}^{5}$ cm/sec ($\frac{1}{3}\sqrt{3}$ times the Debye velocity). The inverse of the normal process phonon lifetime has a value ${{T}_{N}}^{\ensuremath{-}1}=4.49\ifmmode\times\else\texttimes\fi{}{10}^{4}{T}^{4}$ ${\mathrm{sec}}^{\ensuremath{-}1}$. Scattering due to the hole-phonon interaction is observed for ballistic $L$ modes propagating along the ${C}_{3}$ axis.
TL;DR: In this paper, it was shown that a black hole in its final state can be endowed with no exterior scalar, vector, or spin-2 meson fields, and therefore a useful definition of baryon number cannot be given for such an object.
Abstract: The following result is stated: A black hole in its final state can be endowed with no exterior scalar, vector, or spin-2 meson fields. We conclude that such a black hole is not subject to the strong interactions which are mediated by meson fields such as the $\ensuremath{\pi}$, $\ensuremath{\rho}$, and $f$, and that consequently a useful definition of baryon number cannot be given for such an object.
TL;DR: In this paper, high-resolution x-ray photoelectron spectra of the total valence bands of crystalline and amorphous silicon and germanium are reported.
Abstract: High-resolution x-ray photoelectron spectra of the total valence bands of crystalline and amorphous silicon and germanium are reported. For the crystals, the spectra yield results that are strikingly similar to current theoretical calculations of the electron density of states, $\ensuremath{\rho}(E)$. Amorphous Si and Ge exhibit definite band structures that are similar to one another but markedly different from the crystalline results. They agree very well with the theoretical model of Joannopoulos and Cohen.
TL;DR: In this paper, a resonant mechanism was proposed to cause significant absorption of energy from intense laser pulses in plasma targets, and the energy should be deposited in such a way as to form a very non-Maxwellian high-temperature tail on the electron velocity distribution.
Abstract: It is proposed that a resonant mechanism should cause significant absorption of energy from intense laser pulses in plasma targets, and that the energy should be deposited in such a way as to form a very non-Maxwellian high-temperature tail on the electron velocity distribution
TL;DR: In this paper, the structure of the $4d$ excitations in Pr and the $2p$ excitation of Si using a single crystal was investigated using the continuous spectrum of synchrotron radiation.
Abstract: Because of the similarity between photoelectric yield and photoabsorption spectra in the soft x-ray region, "yield spectroscopy" can be used as a successful method for investigating fine structure in the electronic excitation spectra of solids. The continuous spectrum of synchrotron radiation is especially appropriate for such measurements. We reinvestigated the structure of the $4d$ excitations in Pr and the $2p$ excitations of Si using a single crystal.
TL;DR: In this article, a statistical expression for the surface tension of a liquid-vapor interface is derived, which contains the density profile and the direct correlation function in the vicinity of the interface.
Abstract: We derive a statistical mechanical expression for the surface tension of a liquid-vapor interface. It contains the density profile and the direct correlation function in the vicinity of the interface. When a local Ornstein-Zernike approximation is made on the direct correlation function, the surface-tension theory of Fisk and Widom is obtained.
TL;DR: In this paper, the damping coefficient of a large-amplitude electron plasma wave was derived from Poisson's equation and a time-dependent frequency shift was obtained which produces a phase shift that should be amenable to experimental observation.
Abstract: The shift in the complex frequency of a large-amplitude electron plasma wave is formulated in terms of a new subtraction procedure which reproduces the damping coefficient of Mazitov and of O'Neil directly from Poisson's equation. A time-dependent frequency shift is obtained which produces a phase shift that should be amenable to experimental observation. The results are interpretated in terms of simultaneous conservation of momentum and energy in the wave frame.
TL;DR: In this paper, a limiting intensity for light propagation in transparent liquids and solids is determined by avalanche ionization over a wide range of pulse durations, wavelengths, and band gaps, based on the thickness dependence of the dc breakdown.
Abstract: A limiting intensity is shown to exist for light propagation in transparent liquids and solids. In pure bulk materials it is determined by avalanche ionization over a wide range of pulse durations, wavelengths, and band gaps. The ionization rate per unit time is deduced from the thickness dependence of the dc breakdown. The negative real part of the index of refraction of the carriers stabilizes the size of self-focused filaments.
TL;DR: In this article, a normal molecular vibration is strongly excited by a picosecond light pulse and the rise and decay of the excess population of the first excited vibrational state (electronic ground state) is observed with a delayed probe pulse.
Abstract: A normal molecular vibration is strongly excited by a picosecond light pulse. The rise and decay of the excess population of the first excited vibrational state (electronic ground state) is observed with a delayed probe pulse. These measurements give, for the first time, values of the lifetimes of molecular vibrations in liquids.