# Twisted Bilayer Graphene: Moire' is Different

A single layer graphene hides many body effects in the dense viscous
fluid of p-pi electrons, Bilayer graphene, with AA and AB registry, on
the other hand, exposes some of them. A twisted bilayer springs more
surprises. We discuss recently seen superconductivity in twisted bilayer
graphene. Resonating valence bond (RVB) physics contained in the dense
electron fluid in graphene is invoked [1]. RVB fails to produce
superconductivity in neutral graphene, as carrier are absent at the
Fermi level. In a twisted bilayer, interlayer tunneling adds equal
number of electron and hole carriers in Moire superlattice of dominant
AA registry. These carriers use RVB pairing and develop charge -2e and
+2e Cooper pair correlations, in spite of Coulomb repulsions. Resulting
Moire lattice of Cooper pair puddles form a Josephson lattice. Coulomb
blockade makes it a Bosonic Mott insulator. Gate voltage dopes the Bose
Mott insulator and interesting consequences follow.