  The Grobe--Eberly doublet phenomenon occurs in photoelectron distributions
when the remaining ion is dressed by a field. As was recently shown, the
doublet can be interpreted as a signature of quantum entanglement between
photoelectrons and strongly coupled ions. However, the dressed state nature of
the ion prevents detection of the entanglement by straightforward coincidence
detection. Here, we find that odd (zero-area) envelopes can substantially delay
the generation of entanglement, but also modify the dynamics such that the
doublet transforms into unique channel-resolved photoelectron distributions.
Because these distributions can be used to correlate with the internal state of
the ion, our proposed scheme opens up for detection of quantum entanglement,
between photoelectrons and stongly-coupled ions, without a need for quantum
phase measurements.
