http://www.researchonline.mq.edu.au/vital/access/services/Feed ${session.getAttribute("locale")} 5 http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:5878 Coherent population trapping is demonstrated in single nitrogen-vacancy centers in diamond under optical excitation. For sufficient excitation power, the fluorescence intensity drops almost to the background level when the laser modulation frequency matches the 2.88 GHz splitting of the ground states. The results are well described theoretically by a four-level model, allowing the relative transition strengths to be determined for individual centers. The results show that all-optical control of single spins is possible in diamond. 2010-01-27T22:25:14.046Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:5877 Lifetime-limited optical excitation lines of single nitrogen-vacancy (NV) defect centers in diamond have been observed at liquid helium temperature. They display unprecedented spectral stability over many seconds and excitation cycles. Spectral tuning of the spin-selective optical resonances was performed via the application of an external electric field (i.e., the Stark shift). A rich variety of Stark shifts were observed including linear as well as quadratic components. The ability to tune the excitation lines of single NV centers has potential applications in quantum information processing. 2010-01-27T22:25:13.914Z ]]> http://www.researchonline.mq.edu.au/vital/access/manager/Repository/mq:6506 It is shown that complete information on the micromaser cavity field correlation function and hence the spectrum for the cavity field at absolute zero is encoded on the atomic beam exiting from the cavity. A possible means of measuring the atomic beam correlation function is discussed. 2010-01-27T22:17:00.464Z ]]>