  We report the detection of weak mean longitudinal magnetic fields in the
Herbig Ae double-lined spectroscopic binary AK Sco and in the presumed
spectroscopic Herbig Ae binary HD95881 using observations with the High
Accuracy Radial velocity Planet Searcher polarimeter (HARPSpol) attached to the
European Southern Observatory's (ESO's) 3.6m telescope. Employing a multi-line
singular value decomposition (SVD) method, we detect a mean longitudinal
magnetic field <B_z>=-83+-31G in the secondary component of AK Sco on one
occasion. For HD95881, we measure <B_z>=-93+-25G and <B_z>=105+-29G at two
different observing epochs. For all the detections the false alarm probability
is smaller than 10^-5. For AK Sco system, we discover that accretion diagnostic
Na I doublet lines and photospheric lines show intensity variations over the
observing nights. The double-lined spectral appearance of HD95881 is presented
here for the first time.
