Cavity dark states for quantum computing

We show that two multilevel atoms can perform quantum communication with ea ch other via interaction with an enclosing cavity containing no photons. Th e physical mechanism is analogous to the way populations can be exchanged b etween the extremal states in a three level system via adiabatic following, without populating the intermediate states. The combined system of the two atoms, the cavity, and two laser beams contains a dark state corresponding to the cavity in its ground state. Using a counter-intuitive pulse sequenc e, quantum information can be transferred adiabatically from one atom to th e other via this cavity, dark state. This process can be used to circumvent the effect of cavity decay in a quantum computer formed by cavity intercon nected qubits. (C) 2001 Elsevier Science B.V. All rights reserved.