Nuclear Magnetometry Study of Spin Dynamics in Bilayer Quantum Hall   Systems
  We performed a nuclear magnetometry study on quantum Hall ferromagnet with a bilayer total filling factor of $\nu_{\rm{tot}} = 2$. We found not only a rapid nuclear relaxation but also a sudden change in the nuclear spin polarization distribution after a one-second interaction with a canted antiferromagnetic phase. We discuss the possibility of observing cooperative phenomena coming from nuclear spin ensemble triggered by electrons with collective spin interactions. 
M. H. Fauzi, S. Watanabe, and Y. Hirayama
cond-mat.mes-hall