  We interpret the Holographic Conjecture in terms of quantum bits (qubits).
N-qubit states are associated with surfaces that are punctured in N points by
spin networks' edges labeled by the spin-1/2 representation of SU(2), which are
in a superposed quantum state of spin "up" and spin "down". The formalism is
applied in particular to de Sitter horizons, and leads to a picture of the
early inflationary universe in terms of quantum computation. A discrete
micro-causality emerges, where the time parameter is being defined by the
discrete increase of entropy. Then, the model is analysed in the framework of
the theory of presheaves (varying sets on a causal set) and we get a quantum
history. A (bosonic) Fock space of the whole history is considered. The Fock
space wavefunction, which resembles a Bose-Einstein condensate, undergoes
decoherence at the end of inflation. This fact seems to be responsible for the
rather low entropy of our universe.
