Time-resolved measurements of single electron spins using continuous wave lasers

Applications such as spin-based quantum computing require that the dynamics of single spins are monitored. Single spins produce a small signal and measurement is further complicated by the background from the large number of neighboring spins. We have developed a time-resolved Kerr rotation technique that uses continuous wave lasers. This technique is able to resonantly address a particular spin. Furthermore, it provides an efficient means of data collection that allows for more signal averaging. Finally, we decrease the background and increase the light-matter interaction by utilizing a solid-immersion lens. We will describe our recent efforts to measure single spins in GaAs/AlGaAs fluctuation-type quantum dots.