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Q: Quantenoptik
Q 37: Poster: Quanteneffekte
Q 37.21: Poster
Thursday, March 18, 1999, 16:30–18:30, PH
Coherent Population Transfer Beyond the Adiabatic Limit: Generalized Matched Pulses and Higher-order trapping states — •M. Fleischhauer1, R. G. Unanyan2,3, B. W. Shore2,4, and K. Bergmann2 — 1Sektion Physik, Ludwig-Maximilians Universit"at, D-80333 M"unchen, Germany — 2Fachbereich Physik der Universit"at Kaiserslautern, Postfach 3049, D-67653 Kaiserslautern — 3Institute for Physical Research of Armenian National Academy of Sicences, Ashtarak-2, 378410, Armenia — 4LLNL, Livermore CA 94550, USA
We show that the physical mechanism of STIRAP [1] in a three-level atomic system with a closed loop of coherent couplings (loop-STIRAP) [2] is not the adiabatic rotation of the dark-state of the Hamiltonian but the rotation of a higher-order trapped state in a generalized adiabatic basis. The concept of generalized trapped states allows to construct pulse sequences which lead to an optimum population or coherence transfer also for small pulse areas and gives the possibility to obtain analytic solutions for the atomic dynamics. If pump and Stokes pulses fulfill certain conditions the effective 3× 3 coupling matrix factorizes at a specific point of the iteration. In this case the atomic dynamics reduces to a two-level problem with a real coupling which can be solved analytically. We discuss population transfer with second and third-order matched pulses for several examples.
[1] K. Bergmann, et al. Rev. Mod. Physics, 70, 1003, (1998)
[2] R. G. Unanyan, et al. Opt. Comm. 139, 48, (1997)