• LETTERS
  • General Physics
  • Elementary Particles and Fields
  • Nuclear Physics
  • Atomic, Molecular, and Optical Physics
  • Nonlinear Dynamics, Fluid Dynamics, Classical Optics, Etc.
  • Plasma and Beam Physics
  • Condensed Matter: Structure, Etc.
  • Condensed Matter: Electronic Properties, Etc.
• COMMENTS
• ERRATA

LETTERS

General Physics

•	Space-time as a causal set Luca Bombelli, Joohan Lee, David Meyer, and Rafael D. Sorkin pp. 521-524 [View Page Images , PDF (723 kB), or Buy this Article (Use Article Pack) ]

•	Relativistic, many-particle Lagrangean for electromagnetic interactions R. A. Moore, T. C. Scott, and M. B. Monagan pp. 525-527 [View Page Images , PDF (546 kB), or Buy this Article (Use Article Pack) ]

Elementary Particles and Fields

•	Simple discrete symmetries in phenomenologically viable E6 superstring models Manuel Drees and Xerxes Tata pp. 528-531 [View Page Images , PDF (752 kB), or Buy this Article (Use Article Pack) ]

•	Operator regularization of Green’s functions D. G. McKeon and T. N. Sherry pp. 532-534 [View Page Images , PDF (400 kB), or Buy this Article (Use Article Pack) ]

Nuclear Physics

•	First observation of a near-harmonic vibrational nucleus A. Aprahamian, D. S. Brenner, R. F. Casten, R. L. Gill, and A. Piotrowski pp. 535-538 [View Page Images , PDF (542 kB), or Buy this Article (Use Article Pack) ]

Atomic, Molecular, and Optical Physics

•	Exact tricritical exponents for polymers at the FTHETA point in two dimensions Bertrand Duplantier and Hubert Saleur pp. 539-542 [View Page Images , PDF (606 kB), or Buy this Article (Use Article Pack) ]

•	Squeezing of spontaneous emission in a laser J. Gea-Banacloche pp. 543-546 [View Page Images , PDF (575 kB), or Buy this Article (Use Article Pack) ]

Nonlinear Dynamics, Fluid Dynamics, Classical Optics, Etc.

•	Single-mode operation of a high-power, step-tunable gyrotron K. E. Kreischer and R. J. Temkin pp. 547-550 [View Page Images , PDF (587 kB), or Buy this Article (Use Article Pack) ]

Plasma and Beam Physics

•	Chaotic behavior and period doubling in plasmas P. Y. Cheung and A. Y. Wong pp. 551-554 [View Page Images , PDF (602 kB) , Figure Images, or Buy this Article (Use Article Pack) ]

Condensed Matter: Structure, Etc.

•	Wetting phenomena of binary liquid mixtures on chemically altered substrates Douglas J. Durian and Carl Franck pp. 555-558 [View Page Images , PDF (576 kB), or Buy this Article (Use Article Pack) ]

•	Role of multiple scattering in x-ray photoelectron spectroscopy and Auger-electron diffraction in crystals William F. Egelhoff pp. 559-562 [View Page Images , PDF (612 kB), or Buy this Article (Use Article Pack) ]

•	An inference of high atom densities in solid tritium for nuclear magnetic resonance measurements James R. Gaines, James D. Sater, Evelyn M. Fearon, P. C. Souers, Fred E. McMurphy, and Evan R. Mapoles pp. 563-566 [View Page Images , PDF (622 kB), or Buy this Article (Use Article Pack) ]

•	Phonon ringing and anharmonicity effects in core spectra A. Mansour and S. E. Schnatterly pp. 567-569 [View Page Images , PDF (461 kB), or Buy this Article (Use Article Pack) ]

•	Ab initio determination of a structural phase transition temperature K. M. Rabe and J. D. Joannopoulos pp. 570-573 [View Page Images , PDF (531 kB), or Buy this Article (Use Article Pack) ]

•	Mode anharmonicity in molecular crystals studied by piezomodulated Raman spectrosocpy K. M. White and C. J. Eckhardt pp. 574-577 [View Page Images , PDF (542 kB), or Buy this Article (Use Article Pack) ]

Condensed Matter: Electronic Properties, Etc.

•	Spin localization in Si:P—direct evidence from 31P NMR H. Alloul and P. Dellouve pp. 578-581 [View Page Images , PDF (620 kB), or Buy this Article (Use Article Pack) ]

•	Two-dimensional open-orbit edge states: A new type of quantum oscillation M. Ya. Azbel and P. M. Chaikin pp. 582-585 [View Page Images , PDF (570 kB), or Buy this Article (Use Article Pack) ]

•	Nature of the Griffiths phase A. J. Bray pp. 586-589 [View Page Images , PDF (608 kB), or Buy this Article (Use Article Pack) ]

•	New configuration-coordinate model for the ground, excited, and metastable states of EL2 in GaAs Yasunori Mochizuki and Toshiaki Ikoma pp. 590-593 [View Page Images , PDF (665 kB), or Buy this Article (Use Article Pack) ]

•	Test for low-Q, ‘‘infrared’’ spin-fluctuation effects in heavy fermions and 3He P. C. Stamp pp. 594-596 [View Page Images , PDF (437 kB), or Buy this Article (Use Article Pack) ]

•	Optical pair interactions in the four-wave mixing spectrum of Nd3+-doped β’’-Na-alumina S. C. Rand, J. F. Lam, R. S. Turley, R. A. McFarlane, and O. M. Stafsudd pp. 597-600 [View Page Images , PDF (568 kB), or Buy this Article (Use Article Pack) ]

COMMENTS

•	Comment on ‘‘Excitonic coupling in GaAs/GaAlAs quantum wells in an electric field’’ Gerrit E. Bauer and Tsuneya Ando pp. 601 [View Page Images , PDF (161 kB), or Buy this Article (Use Article Pack) ]

•	Viña Iet al.P reply L. Vina, R. T. Collins, E. E. Mendez, and W. I. Wang pp. 602 [View Page Images , PDF (52 kB), or Buy this Article (Use Article Pack) ]

•	Raman scattering from fractal structures T. Keyes and T. Ohtsuki pp. 603 [View Page Images , PDF (153 kB), or Buy this Article (Use Article Pack) ]

•	Boukenter Iet al.P reply A. Boukenter, B. Champagnon, E. Duval, and J. Serughetti pp. 604 [View Page Images , PDF (87 kB), or Buy this Article (Use Article Pack) ]

•	Comment on ‘‘Signature of g boson in the interacting-boson model from g-factor variations’’ Thomas D. Cohen pp. 605 [View Page Images , PDF (166 kB), or Buy this Article (Use Article Pack) ]

•	Comment on ‘‘Large intensity fluctuations for wave propagation in random media’’ C. A. Condat pp. 606 [View Page Images , PDF (152 kB), or Buy this Article (Use Article Pack) ]

•	Necessity of three or more generations for calculable Dirac neutrino masses in E6 superstring models Ernest Ma pp. 607 [View Page Images , PDF (140 kB), or Buy this Article (Use Article Pack) ]

ERRATA

•	X-Ray Scattering from Sodium-Doped Polyacetylene: Incommensurate-Commensurate and Order-Disorder Transformations M. Winokur, Y. B. Moon, A. J. Heeger, J. Barker, D. C. Bott, and H. Shirakawa pp. 608 [View Page Images or PDF (28 kB) ]

•	Direct Subpicosecond Measurement of Carrier Mobility of Photoexcited Electrons in Gallium Arsenide M. C. Nuss, D. H. Auston, and F. Capasso pp. 608 [View Page Images or PDF (28 kB) ]