  We present ALMA observations of rest-frame far-infrared continuum and [CII]
line emission in two z=6.4 quasars with black hole masses of ~10^8 M_sun. CFHQS
J0210-0456 is detected in the continuum with a 1.2 mm flux of 120+/-35 microJy,
whereas CFHQS J2329-0301 is undetected at a similar noise level. J2329-0301 has
a star formation rate limit of <40 M_sun/yr, considerably below the typical
value at all redshifts for this bolometric luminosity. By comparison with hydro
simulations, we speculate that this quasar is observed at a relatively rare
phase where quasar feedback has effectively shut down star formation in the
host galaxy. [CII] emission is also detected only in J0210-0456. The ratio of
[CII] to far-infrared luminosity is similar to that of low redshift galaxies of
comparable luminosity, suggesting the previous finding of an offset in the
relationships between this ratio and far-infrared luminosity at low- and
high-redshift may be partially due to a selection effect from the limited
sensitivity of previous observations. The [CII] line of J0210-0456 is
relatively narrow (FWHM=189+/-18 km/s), indicating a dynamical mass
substantially lower than expected from the local black hole - velocity
dispersion correlation. The [CII] line is marginally resolved at 0.7"
resolution with the blue and red wings spatially offset by 0.5" (3 kpc) and a
smooth velocity gradient of 100 km/s across a scale of 6 kpc, possibly due to
rotation of a galaxy-wide disk. These observations are consistent with the idea
that stellar mass growth lags black hole accretion for quasars at this epoch
with respect to more recent times.
