  We calculate logarithmic negativity, a quantum entanglement measure for mixed
quantum states, in quantum error-correcting codes and find it to equal the
minimal cross sectional area of the entanglement wedge in holographic codes
with a quantum correction term equal to the logarithmic negativity between the
bulk degrees of freedom on either side of the entanglement wedge cross section.
This leads us to conjecture a holographic dual for logarithmic negativity that
is related to the area of a cosmic brane with tension in the entanglement wedge
plus a quantum correction term. This is closely related to (though distinct
from) the holographic proposal for entanglement of purification. We check this
relation for various configurations of subregions in AdS${}_3$/CFT${}_2$. These
are disjoint intervals at zero temperature, as well as a single interval and
adjacent intervals at finite temperature. We also find this prescription to
effectively characterize the thermofield double state. We discuss how a
deformation of a spherical entangling region complicates calculations and
speculate how to generalize to a covariant description.
