Multichannel quantum control

The CCAP solution to the multichannel quantum control (MCQC) problem [249] is based on the multipath Raman scheme shown in Figure 3.20. One couples the initial state 0) and the degenerate = 1,...,M) target continuum states via N nondegenerate intermediate bound levels k) k =... 

Cold alkali metal atoms have a variety of magnetically tunable resonances that have been exploited in a number of experiments to control the properties of ultracold quantum gases or to make cold molecules. For the most part, experiments have succeeded with species that either do not have inelastic loss channels, or, if they do, the loss rates are very small. Thus, for practical purposes, we can set the resonance decay rate yc = 0 in examining a wide class of magnetically tunable resonances. While general coupled channel methods can be setup to solve the multichannel Schrodinger equation [1], we will use simpler models to explain the basic features of tunable Feshbach resonance states. 

Equations 8.40 and 8.41 show that the time-dependent amplitudes and phases of the laser pulses define the temporal structure of the photoassociated waveform. This is true in the multichannel as well as in the single-channel AREA. We now assume that all the laser pulses have similar simple time profiles, and concentrate on using PA for determining the multichannel structure of the input wavepacket. The measurement is based on controlling the interference of quantum pathways during AREA, each pathway corresponding to the adiabatic passage via one of the intermediate 1)... n) states. 

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