Spin Bose-glass phase in bilayer quantum Hall systems at v=2

We develop an effective spin theory to describe magnetic properties of the nu = 2 quantum Hall bilayer systems. In the absence of disorder this theory agrees with the microscopic Hartree-Fock calculations, and for finite diso rder it predicts the existence of a novel spin Bose-glass phase. The Bose g lass is characterized by the presence of domains of canted antiferromagneti c phase with zero average antiferromagnetic order and short range correlati ons. It has infinite antiferromagnetic transverse susceptibility and finite longitudinal spin susceptibility. Transition from the canted antiferromagn etic phase to the spin Bose-glass phase is characterized by a universal val ue of the spin conductance.