Speaker
Description
Using the well-known Autler-Townes effect, we have implemented a novel quantum memory in our laboratory in a medium of laser-cooled rubidium atoms. This new method relies on the absorption of the signal over a wide spectral region, making it inherently broadband and well-suited to quantum memory applications. This Autler-Townes splitting (ATS) protocol facilitates dynamical control of coherent optical signals for the storage and manipulation of broadband optical pulses. We experimentally demonstrate the proof-of-principle of this technique for several applications in a laser-cooled sample of $^{87}$Rb atoms: the storage of short ($\geq$20 ns) optical signals; the compression and stretching of optical pulses in both time and frequency domains; coherent temporal beamsplitting operations; and wavelength conversion. Additionally, weak optical pulses with less than one average photon per pulse can be stored and retrieved with this method, demonstrating the potential for a broadband quantum memory. Our simulations of this protocol, using the Maxwell-Bloch equations, show that the ATS memory has significant technical advantages over previous techniques, as it is less demanding of resources like laser power or atomic optical density. Furthermore, this protocol is readily generalized to any three-level system and should prove useful across domains of quantum technology.
