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. Author manuscript; available in PMC: 2013 Sep 1.
Published in final edited form as: Nat Photonics. 2013 Mar;7(3):219–222. doi: 10.1038/nphoton.2012.358

Figure 1. Experimental configuration and mapping sequence.

Figure 1

a, A 40Ca+ ion is confined in a linear Paul trap (indicated schematically by two trap tips) and positioned at the antinode of an optical cavity. A bichromatic 393 nm field drives a pair of Raman transitions, generating a single cavity photon. The beam is linearly polarized in the z^ direction and propagates along x^. An external magnetic field is chosen parallel to z^, orthogonal to the cavity axis y^, in order to drive π transitions. The measurement basis of photons exiting the cavity is set by half- and quarter-waveplates (L/2, L/4). Photons are then separated by a polarizing beamsplitter (PBS) for detection on avalanche photodiodes (APD1, APD2). Tables indicate the polarization of photons at APD1 and APD2 corresponding to three measurement bases. b, Two laser pulses at 729 nm (1,2) prepare the ion in a superposition of levels S and S′. This superposition is subsequently mapped onto the vertical (V ) and horizontal (H) polarization of a cavity photon. The 393 nm laser and the cavity field couple S and S′ to the metastable D level. The bichromatic laser field is detuned from levels P and P′ by Δ1 and Δ2 (approximately 400 MHz) and has Rabi frequencies Ω1 and Ω2.