QDY_nam

[jya@pipeline.com (John Young)]

   Science, 30 August 1996: 
 
   "Enforcing Coherent Evolution in Dissipative Quantum 
   Dynamics" 
 
   Cirac, Pellizzari, Zoller 
 
      [Precis] The major obstacle to the preparation and 
      manipulation of many-particle entangled states is 
      decoherence due to the coupling of the system to the 
      environment. A scheme to correct for the effects of 
      decoherence and enforce coherent evolution in the 
      system dynamics is described and illustrated for the 
      particular case of the ion-trap quantum computer. 
 
   The preparation and manipulation of N-particle entangled 
   states is fundamental to the investigation of basic 
   aspects of quantum mechanics and is the basis of 
   applications such as quantum computation, teleportation, 
   cryptography. and spectroscopy. 
 
   The error correction schemes proposed so far have focused 
   on preserving a given entangled state (memory errors). We 
   introduce a method to correct for the effects of 
   decoherence in the dynamical proccss of preparation and 
   modification of entangled states (gate errors). We 
   illustrate our scheme in the context of the ion-trap QC. 
 
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