Robust state preparation in a degenerate four-state system

  • A. Karpati
  • Z. Kis
  • P. Adam


A robust method utilizing a combination of optical pumping and a series of coherent excitation processes is developed for preparing any pure and a wide class of mixed quantum states in the decoherence-free ground-state subspace of a degenerate four-state system. For a given pulse sequence the same final state is obtained regardless of the initial state of the system. An example is presented where a pure state is prepared by a series of excitation processes in the two-dimensional dark subspace of the atom.


mixed state preparation incoherent coherent 


32.80.Qk 42.65.Dr 33.80.Be 


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Copyright information

© Akadémiai Kiadó 2005

Authors and Affiliations

  • A. Karpati
    • 1
  • Z. Kis
    • 1
  • P. Adam
    • 1
    • 2
  1. 1.Department of Nonlinear and Quantum Optics, Research Institute for Solid State Physics and OpticsHungarian Academy of SciencesBudapestHungary
  2. 2.H.A.S. Research Group for Nonlinear and Quantum Optics, and Institute of PhysicsUniversity of PécsPécsHungary

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