  In this letter we introduce a complete photonic logic gate architecture,
making use of the non-linear and spintronic properties of exciton-polaritons in
semiconductor microcavities. This hybrid light-matter design is highly compact
and offers the advantages expected of photonic circuits including: no
distance-dependent loss or signal gradation; electrical isolation and immunity
to electromagnetic interference; reduced error-checking overhead; and direct
coupling to external light, useful for fibre optic communication.
