title: Two-roton bound state in the fractional quantum hall effect
abstract: The true nature of the lowest-energy, long-wavelength neutral excitation of the fractional quantum Hall effect has been a long outstanding problem. In this Letter, we establish that it is a two-roton bound state.
authors.affiliation: Department of Physics, 104 Davey Laboratory, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
authors.initials: K
authors.lastname: Park
authors.initials: JK
authors.lastname: Jain