The Center "Leo Apostel" in collaboration with the Doctoral Programme 
of the VUB, invites everybody to the 24th of its interdisciplinary 
seminars in the series "Foundations". In this series CLEA invites 
scholars that are actively engaged in the research on the foundations 
of a particular discipline. Their lectures will always be directed to 
an interdisciplinary audience, and the discussions aim at confronting 
the foundations of the different disciplines.


           Greenberger-Horne-Zeilinger (GHZ) correlations: 
           **********************************************
          paradox within the Einstein-Podolsky-Rosen paradox
          **************************************************

                          by Marek Zukowski
                          *****************

        (Institute of Theoretical Physics and Astrophysics,
                    University of Gdansk, Poland)


17 September 1997 at 5 p.m. in room 3B213 (building B, third floor)
Vrije Universiteit Brussel, Campus Oefenplein .


About the lecture  
-----------------

During these last decades one of the mysterious aspects of quantum 
mechanics - predicted by the theory and analysed in famous situations 
such as the Einstein- Podolsky-Rosen thought experiment - has been 
revealed to exist experimentally. This aspect is now referred to as 
'quantum entanglement', i.e. the entanglement of quantum particles 
over macroscopic distances, and the strange and counter intuitive 
effects that go together with this special situation. In this lecture 
we want to present a still more peculiar and amazing case of this 
quantum entanglement, first presented by Greenberger, Horne and 
Zeilinger, and therefore referred to as GHZ-entanglement. It concerns 
quantum entanglement of three or more particles. One could say that 
if Einstein Podolsky and Rosen had known about GHZ-entanglement they 
would never have written their famous paper! The first part of the 
lecture will deal with a general introduction to the GHZ-
entanglement in the context of the Einstein-Podolsky-Rosen paradox. 
The second part will be devoted to the presentation of our (i.e. of 
the people associated with the Quantum Interferometry Group 
Innsbruck) proposal on how to generate such entangled states.

About the speaker
-----------------

Professor Marek Zukowski is one of the world specialists on the 
problem of entanglement and the inventor of many interesting 
experimental realisations of this peculiar quantum effect. He is Head 
of the Quantum Optics Division of the Institute of Theoretical 
Physics and Astrophysics of the University of Gdansk, Poland.  He is 
professor of physics and holds a Ph.D. in physics. Prof. Zukowski 
has been visiting professor at Oxford Wadham College, the University-
GHS Essen, the University of Innsbruck, the University of Santander, 
the University of Palermo, the Institute H. PoincarŽ and the Humboldt 
Univ. Berlin.  In 1994 he received the Individual Award of the 
Ministry of Education for Scientific Research in Poland and in 1994 
he was awarded with the Doctor Habilitatus degree at the University 
Nicolaus Copernicus in Poland. Prof. Zukowski is the Organizer 
of conferences and the editor of books : "Problems in Quantum 
Physics; Gdansk '87", "Problems in Quantum Physics; Gdansk '89", 
"18th International School of Quantum Optics and Spectroscopy; 
Gdansk-Sobieszewo 1990".


The presentations with questions will last about an hour. Afterwards, 
an hour or more is reserved for an in-depth, group discussion of the 
topic. 

More info at the CLEA office: phone 02-644 26 77 or via the Web-page: 
http://pespmc1.vub.ac.be/CLEA/