Description
Cold Rydberg atoms have recently become a promising platform for quantum information processing and quantum simulations due to their specific properties. The Rydberg blockade regime allows us to entangle qubits and to make CNOT and CPhase gates. Optical nanofibers (ONFs) are an excellent tool to interact with such atoms. They are relatively easy to install into experimental setups because of the simplicity of coupling light into and out of them. The evanescent field decaying from the nanofiber can excite the atoms from the ground state or produce a dipole trap to localize them around the nanofiber. A probe light sent through the fiber is sensitive to the presence of the atoms in the vicinity of the nanofiber and can be used to collect information from neutral atom qubits. To have a precise control over such a system one needs to know all the interactions happening between the atoms and the nanofiber material. We exploit a two-photon ladder-type excitation in $^{87}$Rb by using 780 nm magneto-optical trap (MOT) cooling lasers and 480 nm light coming from the evanescent field of an ONF. The 480 nm light is locked by an external vapor cell EIT to a particular Rydberg transition. During the experiment, the MOT is overlapped with the ONF region and, firstly, reaches an equilibrium atom population. Then, the 480 nm laser is turned on, and the atoms in the vicinity of the ONF undergo Rydberg excitation and get lost from the MOT. This process introduces an additional loss rate to the MOT population, which we measure by collecting the fluorescence signal. By scanning the 480 nm light across the transition we observe coherent and incoherent Rydberg excitation processes. The experiment was reproduced for excitation to nS$_{1/2}$, nD$_{3/2}$ and nD$_{5/2}$ Rydberg states for a wide range of principal quantum number, n, values.
| Presenter name | Alexey Vylegzhanin |
|---|---|
| How will you attend ICAP-27? | I am planning on in-person attendance |
