Progress toward a spin squeezed optical atomic clock beyond the standard quantum limit
Boris Braverman, Massachusetts Institute of Technology
State of the art optical lattice atomic clocks have reached a relative
inaccuracy level of order $10^{-18}$, making them the most stable time
references in existence. One of the limitations to the precision of
these clocks is the quantum projection noise caused by the measurement
of the atomic state. This limit, known as the standard quantum limit
(SQL), can be overcome by entangling the atoms. By performing spin
squeezing, it is possible to robustly generate such entanglement and
therefore surpass the SQL of precision in optical atomic clocks. I will
report on recent experimental progress toward realizing spin squeezing
in an ${}^{171}$Yb optical lattice clock. A high-finesse
micromirror-based optical cavity operating in the strong coupling regime
of cavity quantum electrodynamics mediates the atom-atom interaction
necessary for generating the entanglement. By exceeding the SQL in this
state of the art system, we are aiming to advance precision time
metrology and expand the boundaries of quantum control and measurement.