  The ability to precisely discriminate multiple quantum channels is
fundamental to achieving quantum enhancements in data-readout, target
detection, pattern recognition, and more. Optimal discrimination protocols
often rely on entanglement shared between an incident probe and a protected
idler-mode. While these protocols can be highly advantageous over classical
ones, the storage of idler-modes is extremely challenging in practice. In this
work, we investigate idler-free block protocols based on the use of
multipartite entangled probe states. In particular, we focus on a class of
idler-free protocol which uses non-disjoint distributions of multipartite probe
states irradiated over multi-channels, known as dynamic discrimination
protocols. We derive new, analytical bounds for the average error probability
of such protocols in a bosonic Gaussian channel setting, revealing idler-free
strategies that display performance close to idler-assistance for powerful,
near-term quantum sensing applications.
