B Julsgaard et al 2004 J. Opt. B: Quantum Semiclass. Opt. 6 5 doi:10.1088/1464-4266/6/1/002
B Julsgaard1, J Sherson1, J L Sørensen1 and E S Polzik2
Show affiliationsQuantum information protocols utilizing atomic ensembles require preparation of a coherent spin state (CSS) of the ensemble as an important starting point. We investigate the magneto-optical resonance method for characterizing a spin state of caesium atoms in a paraffin coated vapour cell. Atoms in a constant magnetic field are subject to an off-resonant laser beam and an RF magnetic field. The spectrum of the Zeeman sub-levels, in particular the weak quadratic Zeeman effect, enables us to measure the spin orientation, the number of atoms, and the transverse spin coherence time. Notably the use of 894 nm pumping light on the D1 line, ensuring the state F = 4, mF = 4 is a dark state, helps us to achieve spin orientation of better than 98%. Hence we can establish a CSS with high accuracy, which is critical for the analysis of the entangled states of atoms.
Issue 1 (January 2004)
Received 17 June 2003, accepted for publication 8 September 2003
Published 25 September 2003
B Julsgaard et al 2004 J. Opt. B: Quantum Semiclass. Opt. 6 5
R Sainz et al 2005 Nanotechnology 16 S150
C Moore 1991 Nonlinearity 4 199
Douglas J Bakkum et al 2008 J. Neural Eng. 5 310
Seungwon Baek et al JHEP06(2005)017
Howard Baer and Jorge O'Farrill JCAP04(2004)005
Th Thümmler et al 2009 New J. Phys. 11 103007
Daniel Braun et al 1997 J. Phys. A: Math. Gen. 30 L117
Simon J P Meara and Keith A Langmack 1998 Phys. Med. Biol. 43 1359
H Berney et al 2000 J. Micromech. Microeng. 10 223