scispace - formally typeset
Search or ask a question

Showing papers in "Physical Review Letters in 1966"


Journal ArticleDOI
TL;DR: In this paper, it is rigorously proved that at any nonzero temperature, a one- or two-dimensional isotropic spin-S$ Heisenberg model with finite-range exchange interaction can be neither ferromagnetic nor antiferromagnetic.
Abstract: It is rigorously proved that at any nonzero temperature, a one- or two-dimensional isotropic spin-$S$ Heisenberg model with finite-range exchange interaction can be neither ferromagnetic nor antiferromagnetic. The method of proof is capable of excluding a variety of types of ordering in one and two dimensions.

6,236 citations


Journal ArticleDOI
TL;DR: The primary cosmic-ray spectrum has been measured up to an energy of $10^{20}$ eV, and several groups have described projects under development or in mind to investigate the spectrum further, into the energy range of 10^{21}-10^{22} eV as mentioned in this paper.
Abstract: The primary cosmic-ray spectrum has been measured up to an energy of $10^{20}$ eV, and several groups have described projects under development or in mind to investigate the spectrum further, into the energy range $10^{21}-10^{22}$ eV. This note predicts that above $10^{20}$ eV the primary spectrum will steepen abruptly, and the experiments in preparation will at last observe it to have a cosmologically meaningful termination.

2,771 citations



Journal ArticleDOI
TL;DR: In this article, a simple formula for pion scattering on any particle but a soft pion was given, and then extended to the more difficult case of pion-pion scattering.
Abstract: The current commutation ${\mathrm{relations}}^{1}$ and partially conserved axial-vector current (PCAC) ${\mathrm{assumption}}^{2,3}$ allow the calculation of the matrix elements for emission and absorption of any number of soft ${\mathrm{pions}}^{4}$ and, therefore, in particular, determine the scattering length of a pion on any target particle In this note we give a simple formula for pion scattering on any particle but a ${\mathrm{pion}}^{5}$, and then extend this result to the more difficult case of pion-pion scattering

1,244 citations




Journal ArticleDOI
TL;DR: The notion of partially conserved axial-vector current (1) (PCAC) and the current commutation relations that generate the algebra U(2)xU (2) have been successfully applied to the calculation of the axial vector constant renormalization and to the non-leptonic decays of hyperons and K mesons.
Abstract: The notion of a partially conserved axial-vector current (1) (PCAC) and the current commutation relations that generate the algebra U(2)xU(2) have been successfully applied to the calculation of the axial-vector constant renormalization (2) and to the nonleptonic decays of hyperons and K mesons. (3) In this note, we wish to report on further applications of these ideas to the decays of vector mesons.

596 citations



Journal ArticleDOI
TL;DR: In this paper, the conductance of metal-metal oxide-metal tunneling junctions has been observed to increase at certain characteristic bias voltages, which are identified with vibrational frequencies of molecules contained in the barrier.
Abstract: The conductance of metal-metal oxide-metal tunneling junctions has been observed to increase at certain characteristic bias voltages. These voltages are identified with vibrational frequencies of molecules contained in the barrier.

497 citations


Journal ArticleDOI
TL;DR: In this article, effective mass corrections due to emission and reabsorption of persistent spin fluctuations are shown to have a temperature dependence which fits qualitatively that of the low-temperature specific heat of ${\mathrm{He}}^{3}$.
Abstract: Effective-mass corrections due to emission and reabsorption of persistent spin fluctuations are shown to be large in Pd and to have a temperature dependence which fits qualitatively that of the low-temperature specific heat of ${\mathrm{He}}^{3}$.

468 citations




Journal ArticleDOI
TL;DR: In this paper, an experiment on temperature pulse propagation in a bcc crystal grown at 959 atm shows the existence of second sound in the solid below about 058\ifmmode^\circ\else\text degree\fi{}
Abstract: An experiment on temperature pulse propagation in a bcc crystal of $^{3}\mathrm{He}$ grown at 959 atm shows the existence of second sound in the solid below about 058\ifmmode^\circ\else\textdegree\fi{}K In the temperature range $042\ifmmode^\circ\else\textdegree\fi{}\mathrm{K}lTl058\ifmmode^\circ\else\textdegree\fi{}\mathrm{K}$, reflections of the received pulses were observed In the range $058\ifmmode^\circ\else\textdegree\fi{}\mathrm{K}lTl12\ifmmode^\circ\else\textdegree\fi{}\mathrm{K}$, the temperature pulses were observed to propagate diffusively








Journal ArticleDOI
TL;DR: In this paper, high energy photon absorption in space due to electron-positron pair production in photon-photon collision was investigated. But the photon absorption rate was not shown.
Abstract: High energy photon absorption in space due to electron-positron pair production in photon-photon collision


Journal ArticleDOI
TL;DR: In this article, it was reported that a hitherto unexplained optical transition in ZnTe is due to oxygen substituting isoelectronically for Te, and a classification of isoe-lectronic traps into isoeelectronic donors and acceptors was made.
Abstract: It is reported that a hitherto unexplained optical transition in ZnTe is due to oxygen substituting isoelectronically for Te. A classification of isoelectronic traps into isoelectronic donors and acceptors is made. One striking difference between these two classes is apparent in the phonon sidebands of the $J=1$ and $J=2$ transitions occuring at each center.



Journal ArticleDOI
W. L. Faust1, Charles H. Henry1
TL;DR: In this paper, the sum and difference frequency generation were observed when visible laser light is mixed in GaP with each of five infrared laser frequencies near the reststrahl, and the measured infrared frequency dependence of the nonlinear susceptibility, which varies by a factor of 60, was accounted for by theory.
Abstract: Sum and difference frequency generation are observed when visible laser light is mixed in GaP with each of five infrared laser frequencies near the reststrahl. The measured infrared frequency dependence of the nonlinear susceptibility, which varies by a factor of 60, is accounted for by theory.