We present high-resolution ( \sim 35 au ) ALMA Band 6 1.3 mm dust polarization observations of IRAS 16293 .
These observations spatially resolve the dust polarization across the two protostellar sources and toward the filamentary structures between them .
The dust polarization and inferred magnetic field have complicated structures throughout the region .
In particular , we find that the magnetic field is aligned parallel to three filamentary structures .
We characterize the physical properties of the filamentary structure that bridges IRAS 16293A and IRAS 16293B and estimate a magnetic field strength of 23-78 mG using the Davis-Chandrasekhar-Fermi method .
We construct a toy model for the bridge material assuming that the young stars dominate the mass and gravitational potential of the system .
We find that the expected gas flow to each star is of comparable order to the Alfvén speed , which suggests that the field may be regulating the gas flow .
We also find that the bridging material should be depleted in \sim 10 ^ { 3 } yr .
If the bridge is part of the natal filament that formed the stars , then it must have accreted new material .
Alternatively , the bridge could be a transient structure .
Finally , we show that the 1.3 mm polarization morphology of the optically thick IRAS 16293B system is qualitatively similar to dust self-scattering .
Based on similar polarization measurements at 6.9 mm , we propose that IRAS 16293B has produced a substantial population of large dust grains with sizes between 200 and 2000 \mu m .