Copyright by Kirsten Viering 2006 - Raizen Lab - The University of ...
Copyright by Kirsten Viering 2006 - Raizen Lab - The University of ...
Copyright by Kirsten Viering 2006 - Raizen Lab - The University of ...
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frame is obtained <strong>by</strong> expanding the sum,<br />
T(1, 0) = T ′ (1, 0) cos θ(r) + 1 √ 2 T ′ (1, −1) sin θ(r) e −iφ(r) + 1 √ 2 T ′ (1, 1) sin θ(r) e iφ(r) . (5.41)<br />
This has to be true for all angles θ and φ. By choosing θ = φ = 0 we therefore find that<br />
T(1, 0) = T ′ (1, 0) = β0,0. (5.42)<br />
We will use the Wigner-Eckart <strong>The</strong>orem to determine the remaining effective<br />
Raman-Rabi frequencies in the rotated frame; using eq. A.6 we find them to be<br />
β−1,0 = β1,0 = 1<br />
2 β0,0. (5.43)<br />
After doing the transformation to the lab frame using eq. 5.41 the Raman-Rabi fre-<br />
quency become<br />
β0,0(r) = T ′ (1, 0) cos θ(r) = β0,0 cos θ(r) (5.44)<br />
β−1,0(r) = 1 √ 2 T ′ (1, −1) sin θ(r) = 1<br />
β1,0(r) = 1 √ 2 T ′ (1, 1) sin θ(r) = 1<br />
2 √ 2 β0,0 sin θ(r) (5.45)<br />
2 √ 2 β0,0 sin θ(r). (5.46)<br />
We have neglected phase information in these expressions since only the magnitude<br />
<strong>of</strong> the Raman-Rabi frequencies matters for the final state probability. <strong>The</strong> remaining<br />
Raman-Rabi frequencies <strong>of</strong> the initial states with magnetic quantum number m = ±1<br />
can be treated similarly.<br />
<strong>The</strong> final state probability can therefore be determined <strong>by</strong> adding the contribu-<br />
tions from all initially populated states. <strong>The</strong> transfer efficiency is determined <strong>by</strong> the<br />
product <strong>of</strong> the effective Raman-Rabi frequency and the pulse duration, while the prod-<br />
uct <strong>of</strong> the detuning from resonance due to a magnetic field gradient and the pulse dura-<br />
tion determines the resolution. <strong>The</strong> magnitude <strong>of</strong> the external magnetic field influences<br />
the effective detuning (δ − δB(r)), while the direction affects the effective Raman-Rabi<br />
i<br />
frequency β.<br />
39