title: Spin degree of freedom in the nu=1 bilayer electron system investigated by nuclear spin relaxation.
abstract: The nuclear-spin-relaxation rate 1/T(1) has been measured in a bilayer electron system at and around total Landau level filling factor nu=1. The measured 1/T(1), which probes electron spin fluctuations, is found to increase gradually from the quantum Hall (QH) state at low fields through a phase transition to the compressible state at high fields. Furthermore, 1/T(1) in the QH state shows a noticeable increase away from nu=1. These results demonstrate that, as opposed to common assumption, the electron spin degree of freedom is not completely frozen either in the QH or the compressible states.
authors.affiliation: NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi 243-0198, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Kumada
authors.forename: K
authors.initials: K
authors.lastname: Muraki
authors.forename: K
authors.initials: K
authors.lastname: Hashimoto
authors.forename: Y
authors.initials: Y
authors.lastname: Hirayama