Eisenstein, J. P.Pfeiffer, L. N.Spielman, I. B.West, K. W.2004-12-032004-12-0320012001http://hdl.handle.net/2003/56010.17877/DE290R-10373enThe American Physical SocietyPhysical Review Letters530Observation of a Linearly Dispersing Collective Mode in a Quantum Hall Ferromagnet10.1103/PhysRevLett.87.036803article (journal)