%AColombo, Simone%APedrozo-Peñafiel, Edwin%AVuletić, Vladan%BJournal Name: Applied Physics Letters; Journal Volume: 121; Journal Issue: 21 %D2022%I %JJournal Name: Applied Physics Letters; Journal Volume: 121; Journal Issue: 21 %K %MOSTI ID: 10385146 %PMedium: X %TEntanglement-enhanced optical atomic clocks %XRecent developments in atomic physics have enabled the experimental generation of many-body entangled states to boost the performance of quantum sensors beyond the Standard Quantum Limit (SQL). This limit is imposed by the inherent projection noise of a quantum measurement. In this Perspective article, we describe the commonly used experimental methods to create many-body entangled states to operate quantum sensors beyond the SQL. In particular, we focus on the potential of applying quantum entanglement to state-of-the-art optical atomic clocks. In addition, we present recently developed time-reversal protocols that make use of complex states with high quantum Fisher information without requiring sub-SQL measurement resolution. We discuss the prospects for reaching near-Heisenberg limited quantum metrology based on such protocols. %0Journal Article