Institut Henri Poincaré (IHP)

January 4 - April 7,   2006
Paris,  France

Programme

QUANTUM INFORMATION,
COMPUTATION AND COMPLEXITY

 





 
           

    Announcement (pdf)

   Organizers    

   Ph.Grangier   (IOTA, Orsay)
   M.Santha   (LRI, Orsay)
   D.L.Shepelyansky   (LPT, Toulouse)   (photo)

   Secretary    

   Sylvie Lhermitte   (IHP, Paris)



   DESCRIPTION

In last years a new research field of quantum information has emerged on the intersection between quantum physics, computer science and mathematics. Its main idea is to treat information on the basis of quantum mechanics so that computation and communication are done with essentially quantum elements. At present quantum information attracts enormous interest of scientific community becoming the priority research direction for EU, USA and Japan. Private companies also participate in this research (IBM, HP, NEC, NTT, Toshiba and others). There are multiple reasons for this enormous interest. Following Moore's law the miniaturization of electronic components goes on smaller and smaller scales and in few years the quantum effects cannot be ignored. Thus a new type of logic based on many-body quantum mechanics should be developed that by itself represents a new challenge for mathematics and computer science. Also quantum mechanics may be used for cryptography that allows to reach a new level of communication security.


Important results have been obtained in quantum information
during last years. A concept of quantum computer composed of
qubits is developed theoretically. Each qubit represents a two-level
quantum system and it is shown that a precise control of 
one qubit rotations and two-qubit interactions in time 
allow to realize elementary quantum gates. With these elementary
gates universal computations can be performed in the 
finite-dimensional Hilbert space which size grows exponentially
with the number of qubits. A number of quantum algorithms
have been developed which
efficiency overcomes those that are based on classical operations.
The most famous among them is the Shor quantum algorithm
for factorization of integers (linked to RSA coding)
which is exponentially faster than any known classical algorithm.
The Grover quantum search algorithm gives a quadratic speed up.
A significant gain can be also reached for simulation of problems
of quantum evolution and problems of complex dynamics.
Also important theoretical studies
have been done to control quantum errors induced by
external decoherence and internal imperfections 
linked to residual inter-qubit couplings. 
Quantum information introduces absolutely new concepts like
entanglement between qubits 
which is absent in classical computations. This opens new 
horizons  for secure quantum communications with
Einstein-Podolsky-Rosen (EPR) pairs, quantum cryptography
and teleportation.

   TOPICS

The Programme is composed of main and short courses on modern theoretical and experimental aspects of quantum information including:
- quantum algorithms
- quantum communication, teleportation and cryptography
- quantum error correction
- quantum information with continuous variables
- decoherence and quantum chaos induced by imperfections
- solid state implementations of qubits
- quantum computation with cold atoms and ions
- entanglement with Rydberg and cold atoms
- quantum measurements

   Main courses


   Short courses


   Seminars