Arbitrary spin-1 state manipulations and squeezed metrology in a spin-1 BEC.
I will discuss a scheme developed to apply arbitrary transformations to a spin-1 state. The rubidium-87 spin-1 manifold can be manipulated using the combination of a multi-tone microwave pulse and an external light shift. This so-called “tripod” technique boasts a simplicity akin to driving a Rabi cycle and eliminates the need for more complicated, multi-pulse sequences to initialize or measure a particular quantum state. The tripod can be used to construct arbitrary U(3) operators and to make projective measurements of arbitrary observable operators of the spin-1 state. I will describe the experimental implementation of this tripod.
Additionally, I’ll talk about a method for squeezed magnetometry using the spin-1 Bose-Einstein condensate. This scheme shows how spin-nematic squeezing can by transferred to metrologically relevant states; in this case, to produce squeezing in a magnetically-sensitive state. This state can be constructed via a multi-pulse sequence or via the tripod and has a Larmor phase sensitivity enhanced by a factor equivalent to the squeezing parameter.