  We study the phenomenon of quantum synchronization from the viewpoint of
quantum metrology. By interpreting quantum self-sustained oscillators as
dissipative quantum sensors, we develop a framework to characterize several
aspects of quantum synchronization. We show that the quantum Fisher information
(QFI) serves as a system-agnostic measure of quantum synchronization that also
carries a clear operational meaning, viz., it quantifies the precision with
which the amplitude of a weak synchronizing drive can be measured. We extend
our analysis to study many-body oscillators subjected to multiple drives. We
show how the QFI matrix can be used to determine the optimal drive that
maximizes quantum synchronization, and also to quantitatively differentiate the
synchronization responses induced by different drives. Our work highlights
multiple connections between quantum synchronization and quantum metrology,
paving a route towards finding quantum technological applications of quantum
synchronization.
