Pseudospintronics in bilayer graphene

Graphene is composed of two coupled sublattices and therefore supports
an additional quantum number called pseudospin. In bilayer graphene,
pseudospin is determined by the relative amplitude of the wave function
on the two layers, with "up" pseudospin corresponding to the electronic
density on one layer and "down" to the density on the other. We propose
a non-magnetic, pseudospin-based version of a spin valve, in which the
pseudospin polarization in neighbouring regions of a bilayer is
controlled by external gates. Numerical calculations demonstrate a large
on-off ratio of such a device. This finding holds promise for the
realization of "pseudospintronics": a form of electronics based upon the
manipulation of pseudospin analogous to the control of physical spin in
spintronics applications.