Southwest Quantum Information and Technology

Trapped atoms and polarimetry in a nanofiber-based quantum interface

Presenting Author: David Melchior, University of Arizona
Contributing Author(s): Poul Jessen

We describe an experiment to trap and control the collective spin of cold cesium atoms using the evanescent-wave field of a tapered optical fiber (nanofiber). Probe light propagating through the nanofiber is strongly mode-matched to atoms trapped in the evanescent mode, resulting in a high expected optical depth on the order of 10^2. When probe laser light interacts with a trapped atomic sample with high optical depth, the polarization of the light undergoes Faraday rotation proportional to the atomic magnetization. For sufficiently high atom-light coupling, polarimetry of this probe light can measure the magnetization with resolution better than the spin projection noise, at which point measurement back-action can be used for quantum control of the spin. Here, we report experimental progress towards detecting cold atoms samples around a nanofiber, including resonant absorption of ~10% from a single atom.

(Session 5 : Thursday from 5:00pm - 7:00 pm)