  The efficient detection of a single spin is a significant goal of improving
the sensitivity of quantum magnetic-field sensors. Recent results show that a
specific type of entanglement such as Greenberger-Horne-Zeilinger (GHZ) states
can be used as a resource to improve the performance of single spin detection.
However, scalable generation of the GHZ states is experimentally difficult to
realize. It is desirable to use a practical entangled state that can be easily
generated. In this paper, we propose the efficient detection of a single spin
with Dicke states. We show a way to prepare and measure Dicke states via a
global control. Moreover, we investigate how dephasing due to unwanted coupling
with the environment affects the performance of our proposal, and show that
single spin detection with Dicke states with dephasing has a significant
advantage over the classical strategy with separable states. Our results are
important toward realizing entanglement enhanced single spin detection.
