PHYSICAL  REVIEW
                                     LETTERS

Providing rapid publication of short reports of important fundamental research,
with coverage of major advances in all aspects of physics and of developments
with significant consequences across subdisciplines.
  
      Editorial Office                                 Editors
                   
1 Research Road, Box 9000,                         Jack Sandweiss
   Ridge, NY 11961-9000       George Basbas       Stanley G. Brown     Gene L. Wells
   Phone:(516) 591-4060
    Fax: (516) 591-4141       Associate Editor  Senior Assistant Editors  Assistant Editor
   Internet: prl@aps.org      Brant M. Johnson      Jerome Malenfant        Anne Michelsen
					   	 Reinhardt B. Schuhmann
                                                             
   World Wide Web server      Senior Assistants  Assistant to the Editors  Senior Editorial
  http://publish.aps.org/     to the Editors           Sami Mitra                Assistants
                              Robert Garisto                                   Marie Kaplan
                              Christopher Wesselborg                        Paul K. Sherard

                                                 Adjunct Associate Editors
                                                   Raymond E. Goldstein
                                                     Zachary H. Levine
          The                 
American Physical Society                         
   One Physics Ellipse        
 College Park, Maryland      
        20740-3844                   Editorial Board (Divisional Associate Editors)
                                                Jack Sandweiss, Chairman
        President
D. Allan Bromley              S.P. Boughn, J.L. Friedman, E. Vishniac (Astrophysics)
             Yale University  E. Arimondo, M.R. Flannery, R.A. Holt, P. Zoller
                                             (Atomic, Molecular, and Optical Physics)
     President-Elect          P.M. Champion, M. Wortis (Biological Physics)
Andrew M. Sessler                                       W.H. Miller(Chemical Physics)
Lawrence Berkeley Laboratory  G. Bastard, S. Chakravarty, D. Esteve, A.L. Fetter, 
                                Z. Fisk, G. Grest, Y. Imry, J.D. Joannopoulos, 
     Vice-President             D.C. Johnston, G. Kotliar,  A.H. MacDonald, S. Maekawa, 
Jerome I. Friedman              M.A. Moore, M.A. Reed, M. Scheffler, D. Vollhardt, 
     Massachusetts Institute    T.A. Witten, Jr., W. Zwerger(Condensed Matter Physics)
               of Technology

   Executive Officer          G. Ahlers, P.G. De Gennes (Fluid Dynamics)
Judy R. Franz                 F. Bates, M. Muthukumar (High Polymer Physics)
      University of Alabama,  K.C. Kulander, J.C. Miller (Laser Science)	
                  Huntsville  W.F. Egelhoff, Jr., F.J. Himpsel, S.M. Shapiro, 
                                C. Van de Walle, A. Zangwill (Materials Physics)
        Treasurer             G. Fai, R.V. Janssens, B. Keister, R.P. Redwine,
Thomas J. McIlrath              P. Ring, W.A. Zajc (Nuclear Physics)
      University of Maryland       R. Chivukula, J.E. Pilcher, J. Polchinski, S.R. Sharpe, 
                              	 G. Sterman, D. Wyler(Particles and Fields)
     Editor-in-Chief          R. Siemann (Physics of Beams)
Martin Blume                  T.M. Antonsen, J.P. Dahlburg, R. Lovelace,
         Brookhaven National                          M. Mauel (Plasma Physics)
                  Laboratory  F. Laloe (Foundations of Quantum Mechanics)
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Physical Review Letters (ISSN: 0031-9007) is published weekly by The American Physical Society. Copyright 1997 by The American Physical Society.