# My DAMOP 2017 talk

### Generation of atomic spin squeezed states in nanophotonic waveguides using QND measurement

My submission has been accepted to be presented as a talk at the APS 48th Annual Meeting of Atomic, Molecular and Optical Physics and is currently on the program schedule.

Day, Date: Friday, June 9th, 2017

Time, Session: 9:24 AM–9:36 AM, Session T7: Quantum Measurement

Authors:

• Xiaodong Qi (University of New Mexico)
• David Melchior (University of Arizona)
• Poul S. Jessen (University of Arizona)
• Jongmin Lee (Sandia National Labs)
• Yuan-Yu Jau (Sandia National Labs)
• Ivan H. Deutsch (University of New Mexico)

Abstract: Nanophotonic waveguides strongly enhance the entangling strength of the atom-light interface. We study their application to the generation of spin squeezed states of trapped ultracold cesium atoms in two geometries — cylindrical optical nanofibers and square waveguides. We consider two different protocols — squeezing the clock transition by the birefringence coupling and squeezing a spin coherent state via the Faraday interaction. We unify our analysis based on a universal parameter — the optical depth per atom. In calculating the spin squeezing parameter, we have established a set of stochastic master equations to describe the individual and collective spin dynamics. Our simulation shows that $\sim 10$ dB of spin squeezing may be achievable with a few thousands of atoms on these nanophotonic waveguides. Our result can be generalized to other nanophotonic platforms, for implementing non-Gaussian states, and to improve quantum sensing precision using spin squeezing techniques.